Videos uploaded by user “Blockgeeks”
What is Ethereum? Beginners Video Guide
What is Ethereum? https://blockgeeks.com/guides/what-is-ethereum/ By now, almost everyone has heard of Bitcoin. But how many people have heard of Ethereum? Ethereum is a Canadian made blockchain technology that not only acts as a currency, but can execute smart contracts. But what does that actually mean? How does it work? We cover all of that right here! For more blockchain guides, courses, and videos, visit us over at blockgeeks.com! === Is Ethereum similar to Bitcoin? Well, sort of, but not really. Like Bitcoin, Ethereum is a distributed public blockchain network. Although there are some significant technical differences between the two, the most important distinction to note is that Bitcoin and Ethereum differ substantially in purpose and capability. Bitcoin offers one particular application of blockchain technology, a peer to peer electronic cash system that enables online Bitcoin payments. While the Bitcoin blockchain is used to track ownership of digital currency (bitcoins), the Ethereum blockchain focuses on running the programming code of any decentralized application. In the Ethereum blockchain, instead of mining for bitcoin, miners work to earn Ether, a type of crypto token that fuels the network. Beyond a tradeable cryptocurrency, Ether is also used by application developers to pay for transaction fees and services on the Ethereum network.  There is a second type of token that is used to pay miners fees for including transactions in their block, it is called gas, and every smart contract execution requires a certain amount of gas to be sent along with it to entice miners to put it in the blockchain. “Bitcoin is first and foremost a currency; this is one particular application of a blockchain. However, it is far from the only application. To take a past example of a similar situation, e-mail is one particular use of the internet, and for sure helped popularise it, but there are many others.” Dr Gavin Wood, Ethereum Co-Founder What is a smart contract? Smart contract is just a phrase used to describe computer code that can facilitate the exchange of money, content, property, shares, or anything of value. When running on the blockchain a smart contract becomes like a self-operating computer program that automatically executes when specific conditions are met. Because smart contracts run on the blockchain, they run exactly as programmed without any possibility of censorship, downtime, fraud or third party interference. While all blockchains have the ability to process code, most are severely limited. Ethereum is different. Rather than giving a set of limited operations, Ethereum allows developers to create whatever operations they want. This means developers can build thousands of different applications that go way beyond anything we have seen before. “ [Ethereum] blockchain has some extraordinary capabilities. One of them is that you can build smart contracts. It’s kind of what it sounds like. It’s a contract that self-executes, and the contract handles the enforcement, the management, performance, and payment” Don Tapscott The Ethereum Virtual Machine Before the creation of Ethereum, blockchain applications were designed to do a very limited set of operations. Bitcoin and other cryptocurrencies, for example, were developed exclusively to operate as peer-to-peer digital currencies. Developers faced a problem. Either expand the set of functions offered by Bitcoin and other types of applications, which is very complicated and time-consuming, or develop a new blockchain application and an entirely new platform as well. Recognizing this predicament, Ethereum’s creator, Vitalik Buterin developed a new approach.
Views: 25602 Blockgeeks
What is Hashing & Digital Signature in The Blockchain?
What is Hashing & Digital Signature in The Blockchain? https://blockgeeks.com/ Today, we're going to be talking about the word blockchain and breaking it down to understand what does it mean when someone says, "Blockchain." What is hashing? Hashing refers to the concept of taking an arbitrary amount of input data, applying some algorithm to it, and generating a fixed-size output data called the hash. The input can be any number of bits that could represent a single character, an MP3 file, an entire novel, a spreadsheet of your banking history, or even the entire Internet. The point is that the input can be infinitely big. The hashing algorithm [00:01:00] can be chosen depending on your needs and there are many publicly available hashing algorithms. The point is that the algorithm takes the infinite input of bits, applies some calculations to them, and outputs a finite number of bits. For example, 256 bits. What can this hash be used for? A common usage for hashes today is to fingerprint files, also known as check zones. This means that a hash is used to verify that a file has not been [00:01:30] tampered with or modified in any way not intended by the author. If WikiLeaks, for example, publishes a set of files along with their MD5 hashes, whoever downloads those files can verify that they are actually from WikiLeaks by calculating the MD5 hash of the downloaded files, and if the hash doesn't match what was published by WikiLeaks, then you know that the file has been modified in some way. How does the blockchain make use of hashes? [00:02:00] Hashes are used in blockchains to represent the current state of the world. The input is the entire state of the blockchain, meaning all the transactions that have taken place so far and the resulting output hash represents the current state of the blockchain. The hash is used to agree between all parties that the world state is one in the same, but how are these hashes actually calculated? The first hash is calculated for the first block [00:02:30] or the Genesis block using the transactions inside that block. The sequence of initial transactions is used to calculate a block hash for the Genesis block. For every new block that is generated afterwords, the previous block's hash is also used, as well as its own transactions, as input to determine its block hash. This is how a chain of blocks is formed, each new block hash pointing to the block hash that came before it. This system of hashing guarantees that no transaction in the history can be tampered with because if any single part of the transaction changes, so does the hash of the block to which it belongs, and any following blocks' hashes as a result. It would be fairly easy to catch any tampering as a result because you can just compare the hashes. This is cool because everyone on the blockchain only needs to agree on 256 bits to represent the potentially infinite state of the blockchain. The Ethereum blockchain is currently tens of gigabytes, but the current state of the blockchain, as of this recording, is this hexadecimal hash representing 256 bits. What about digital signatures? Digital signatures, like real signatures, are a way to prove that somebody is who they say they are, except that we use cryptography or math, which is more secure than handwritten signatures that can be [00:04:00] easily forged. A digital signature is a way to prove that a message originates from a specific person and no one else, like a hacker. Digital signatures are used today all over the Internet. Whenever you visit a website over ACTPS, you are using SSL, which uses digital signatures to establish trust between you and the server. This means that when you visit Facebook.com, your browser can check the digital signature that came with the web page to verify that it indeed originated from Facebook and not some hacker. In asymmetric encryption systems, users generate something called a key pair, which is a public key and a private key using some known algorithm. The public key and private key are associated with each other through some mathematical relationship. The public key is meant to be distributed publicly to serve as an address to receive messages from other users, like an IP address or home address. The private key is meant to be kept secret and is used to digitally sign messages sent to other users. The signature is included with the message so that the recipient can verify using the sender's public key. This way, the recipient can be sure that only the sender could have sent this message. Generating a key pair is analogous to creating an account on the blockchain, but without having to actually register anywhere. Pretty cool. Also, every transaction that is executed on the blockchain is digitally signed by the sender using their private key. This signature ensures that only the owner of the account can move money out of the account.
Views: 27300 Blockgeeks
What is EOS? How Does it Work?
What is EOS? How Does it Work? https://blockgeeks.com/guides/eos-blockchain/ EOS is a smart contract platform much like Ethereum. EOS, however, promises the ability to perform millions of transactions per second, without any fees! How could this be possible, given the scalability of other major blockchains? In this guide, we dive into what EOS is doing differently to achieve this, and what those choices mean for the network. What Does EOS Blockchain Bring To The Table?   Let’s check out some of the features of EOS. #1 Scalability The biggest problem that the blockchain based space is facing is scalability issue Visa manages 1667 transactions per second while Paypal manages 193 transactions per second. Compared to that, Bitcoin manages just 3-4 transactions per second while Ethereum fairs slightly better at 20 transactions per second. The reason why blockchain-based applications can’t compute that many transactions per second are because each and every node of the network must come to a consensus for anything to go through. EOS are claiming that because they use DPOS aka the distributed proof-of-stake consensus mechanism, they can easily compute millions of transactions per second. We will explore DPOS in a bit. #2 Flexibility Ethereum’s entire system came to a standstill because of the DAO attack. Everything stopped and the community got split because of the hardfork. Because EOS uses DPOS this is unlikely to happen again in their ecosystem. If a DAPP is faulty, the elected block producers can freeze it until the system is taken care of. This is simply an extension of the DPOS system, not every node has to take care of chain maintenance. #3 Usability EOS allows well-defined levels of permission by incorporating features like web toolkit for interface development, self-describing interfaces, self-describing database schemas, and a declarative permission scheme. #4 Governance In EOS the Governance is maintained by establishing jurisdiction and choice of law along with other mutually accepted rules This is usually done via the legally binding constitution. Every single transaction in EOS must include the hash of the constitution to the signature. This, in essence, binds the users to the constitution. The constitution and protocol can be amended by the following process: The change is proposed by the block producer who obtains a 17/21 approval rate The 17/21 approval must be maintained for 30 straight days. All users are required to sign off their transaction using the hash of the new constitution. Block producers adopt changes to the source code to reflect the change in the constitution and propose it to the blockchain using the hash of a git commit. Block producers again need to maintain 17/21 approval for 30 consecutive days. After that, full nodes are given one whole week to adapt to the new changes. Any node that doesn’t follow the new protocol is automatically shut down. So what happens if something like the DAO happens and the EOS system is forced to look for a quick change and solution to the protocol? In emergencies like that the block producers have the power to speed up the amending process. #5 Parallel Processing In parallel processing, program instructions are divided among multiple processors. By doing this, the running time of that program decreases greatly. EOS provides parallel processing of smart contracts through horizontal scalability, asynchronous communication, and interoperability. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 13478 Blockgeeks
What Is Hyperledger?  The Most Comprehensive Video Ever!
What Is Hyperledger? The Most Comprehensive Video Ever! https://blockgeeks.com/guides/hyperledger/ Hyperledger Fabric is one of the most widely used private blockchains, but what is it used for, and how does it work? Niloo walks us through the uses of Hyperledger Fabric, what Chaincode is, and why Private Channels are used! Check out the full course on www.blockgeeks.com Interested in bounties or smart contract auditing? visit http://bountyone.io/ === What is Hyperledger? Let’s start with what Hyperledger is not: Not a company. Not a cryptocurrency. Not a blockchain. Hyperledger is rather something like a hub for open industrial blockchain development. On its website Hyperledger explains: “Hyperledger is an open source collaborative effort created to advance cross-industry blockchain technologies. It is a global collaboration, hosted by The Linux Foundation, including leaders in finance, banking, Internet of Things, supply chains, manufacturing, and Technology.” Hyperledger does not support Bitcoin or any other cryptocurrency. But the platform is thrilled by blockchain technology. Not since the Web itself, the website tells, “has a technology promised broader and more fundamental revolution than blockchain technology.” Blockchains has the potential to “build a new generation of transactional applications that establishes trust, accountability, and transparency at their core while streamlining business processes and legal constraints.” So we have a lot of promises – and we have Hyperledger. With it, the Linux Foundation aims to create an environment in which communities of software developer and companies meet and coordinate to build blockchain frameworks. The Linux Foundation founded the platform in December 2015. In February 2016 it announced the first founding members, in March 2016 ten more members joined. Today Hyperledger has an impressive list of more than 100 members. The list covers a wide scope of well know industry leaders. It includes mobility tech giants like Airbus and Daimler, IT-companies like IBM, Fujitsu, SAP, Huawei, Nokia, Intel and Samsung, financial institutions like Deutsche Börse, American Express, J.P. Morgan, BBVA, BNP Paribas and Well Fargo, as well as Blockchain startups like Blockstream, Netki, Lykke, Factom, bloq and Consensys. A lot of the world’s largest companies in Tech and Finance meet at Hyperledger with some of the hottest blockchain startups. Start Your Free Trial Today Free Trial Something like the executive government of Hyperledger is the committee of leaders. It consists of more than 10 executives, most with decades of experience in Open Source and tight connections to several industries. You’ll find leaders of the Apache Foundation and the W3C Consortium as well as engineers from IBM and more. Some of Hyperledgers’s members, like Richard Brown and Tamas Blumer, already worked with Blockchain for years. For its members, Hyperledger does not only provide technical knowledge and software frameworks but also various contacts to industries and developers. Relatively early in the history of Hyperledger, the project had to make an important decision. Executive Director Brian Behlendorf was asked if there will be an “Hyperledger Coin”, a monetary unit running on the Hyperledger blockchains. Behlendorf answered that the Hyperledger Project itself will never build its own cryptocurrency.
Views: 23314 Blockgeeks
Proof of Work vs. Proof of Stake: A Simple Guide
Proof of Work vs. Proof of Stake https://blockgeeks.com/guides/proof-of-work-vs-proof-of-stake/ If you've researched blockchain, you've probably heard of Proof of Work. It's a popular way for blockchains to keep consensus among their members. But there are a lot of drawbacks to Proof of Work, so many developers are working on an alternative! In this video, we go over what Proof of Work is, and what some of it's problems are. We'll then go over Ethereum's future solution called Proof of Stake, and what it does differently. For more blockchain guides, content, and videos, visit us over at www.blockgeeks.com === Proof of Work vs Proof of Stake: Conclusion Thanks to a PoS system validators do not have to use their computing power because the only factors that influence their chances are the total number of their own coins and current complexity of the network. So this possible future switch from PoW to PoS may provide the following benefits: Energy savings; A safer network as attacks become more expensive: if a hacker would like to buy 51% of the total number of coins, the market reacts by fast price appreciation. This way, CASPER will be a security deposit protocol that relies on an economic consensus system. Nodes (or the validators) must pay a security deposit in order to be part of the consensus thanks to the new blocks creation. Casper protocol will determine the specific amount of rewards received by the validators thanks to its control over security deposits. If one validator creates an “invalid” block, his security deposit will be deleted, as well as his privilege to be part of the network consensus. In other words, the Casper security system is based on something like bets. In a PoS-based system, bets are the transactions that, according to the consensus rules, will reward their validator with a money prize together with each chain that the validator has bet on. So, Casper is based on the idea that validators will bet according to the others’ bets and leave positive feedbacks that are able accelerates consensus.
Views: 12539 Blockgeeks
A Beginner's Guide to Smart Contracts
A Beginner's Guide to Smart Contracts https://blockgeeks.com/guides/smart-contracts/ Smart contracts were an exciting promise of the Ethereum blockchain at its creation. Since then, many more blockchains have launched offering smart contracts in various forms. But what are smart contracts? How can they make the world a better place? Let's dive in to how these self-executing contracts function, as well as some of the real world applications of this technology! For more blockchain guides, courses, and videos: visit us over at blockgeeks.com === Smart contracts help you exchange money, property, shares, or anything of value in a transparent, conflict-free way while avoiding the services of a middleman. The best way to describe smart contracts is to compare the technology to a vending machine. Ordinarily, you would go to a lawyer or a notary, pay them, and wait while you get the document. With smart contracts, you simply drop a bitcoin into the vending machine (i.e. ledger), and your escrow, driver’s license, or whatever drops into your account. More so, smart contracts not only define the rules and penalties around an agreement in the same way that a traditional contract does, but also automatically enforce those obligations. If you are looking for a more detailed walk through of smart contracts please check out our blockchain courses on smart contracts.
Views: 12323 Blockgeeks
Consensus and Mining on the Blockchain
Consensus and Mining on the Blockchain - https://blockgeeks.com/ What is consensus on the blockchain? Consensus basically means that all nodes in a decentralized network must come to an agreement on what is the truth. For bitcoin, all nodes must agree on the transaction history. In a centralized system, all the participants trust that the authority will behave honestly and share the truth with the rest of the members. Since only the trusted party has the power to modify the data, it is straightforward to achieve consensus. Everyone simply accepts and believes what the central authority says. For example, you simply trust your bank will put the correct balance for your account whenever you send and receive money. However, in a decentralized network, there is no central authority and each node does not trust any other nodes. The challenge is how can all the nodes agree on what is the correct state of the shared data? In other words, how can they all achieve consensus with mutual distrust? In computer science, this is known as the Byzantine Generals’ problem, which was originally presented in 1982. The Byzantine Generals’ problem is a description of consensus problems in computer networks. More specifically, how can distributed computer systems handle malfunctioning parts that give conflicting information to different parts of the system? This problem is abstractly described as a group of generals of the Byzantine army camped with their troops surrounding an enemy city. The generals must agree upon a common battle plan and they can only communicate with each other using messengers. However, one or more of the generals may be traitors who will try to confuse the others. The problem is to find an algorithm that ensures the loyal generals will all reach an agreement on the battle plan regardless of what the traitors do. In the case of bitcoin, each general could be thought of as a node in the network and all the honest nodes must agree on what is the true history of transactions. A malicious node can send conflicting transactions to different parts of the network. For example, Bob is a traitor and he sends a transaction stating he sent 10 bitcoins to Alice to one part of the network while sending another transaction stating he sent 10 bitcoins to Carroll to other parts of the network. Let’s assume that Bob only has 10 bitcoins in total, so he is trying to double spend his bitcoins. So what algorithm can be used in the bitcoin network to ensure all the honest nodes recognize Bob sent 10 bitcoins to Alice but reject that he sent 10 bitcoins to Carroll? Bitcoin uses the proof-of-work (PoW) algorithm to ensure all the honest nodes reach a consensus on the true history of transactions. The PoW algorithm concept was first developed in the early 90s to prevent email spamming. It required computers that want to send an email to do some computation work which took some time to complete before sending out the email. This reduced the amount of spam an email server could get in a given period of time. In bitcoin, PoW is used to govern the mechanics of how a new block is added to the blockchain. In the previous lesson, we learned that blockchain is append-only and once a block is added, it cannot be modified. Therefore, we need to ensure that all the honest nodes in the system will add the exact same block to their local copy of the blockchain to achieve consensus. So how does PoW achieve this? First, let’s imagine that all the nodes in the network are allowed to create a new block at anytime instantly. If this were the case, the network would get flooded with too many new blocks, and no one would be able to agree on which of the new blocks should be added to the blockchain. However, in reality, in order for a node to create a new block and broadcast that to the other nodes, it must do some computation work. The computation work is quite intensive and for bitcoin it takes roughly 10 minutes on average for any node to complete. Once a node completes this work, it broadcasts the block to other nodes who verify it. Therefore, all the nodes in the network that want to create a new block must race against each other to be the first one to complete this computation and broadcast their block. This way all the other honest nodes will receive the new block and verify that the proof of work was valid and the transactions inside the block are also correct and then add the block to their local copy of the blockchain. To read more, visit us at https://blockgeeks.com/
Views: 8534 Blockgeeks
Real World Blockchain Applications - Voting
https://blockgeeks.com/ Today we're going to talk about how the blockchain can be used to make democratic systems faster, better, cheaper, and more transparent. We also discuss the downfalls of traditional paper ballot or digital systems. In this guide we talk about elliptic key pairs and signatures. If you want to learn more, head over to blockgeeks.com where we have tons of guides, content, and videos. If you're a blockchain developer looking to earn crypto by auditing contracts, check out our sister site over at bountyone.io
Views: 5125 Blockgeeks
What is a Cryptocurrency Wallet? Simple To understand Video
What is a Cryptocurrency Wallet? Simple To understand Video - https://blockgeeks.com/ What is a Cryptocurrency Wallet? A cryptocurrency wallet is a software program that stores private and public keys and interacts with various blockchain to enable users to send and receive digital currency and monitor their balance. If you want to use Bitcoin or any other cryptocurrency, you will need to have a digital wallet. Cryptocurrency Wallet Guide: A Step-By-Step Tutorial How do they work? Millions of people use cryptocurrency wallets, but there is considerable misunderstanding about how they work. Unlike traditional ‘pocket’ wallets, digital wallets don’t store currency. In fact, currencies don’t get stored in any single location or exist anywhere in any physical form. All that exists are records of transactions stored on the blockchain. Train to Become A Blockchain Developer Start Your Free Trial Today! Cryptocurrency wallets are software programs that store your public and private keys and interface with various blockchain so users can monitor their balance, send money and conduct other operations. When a person sends you bitcoins or any other type of digital currency, they are essentially signing off ownership of the coins to your wallet’s address. To be able to spend those coins and unlock the funds, the private key stored in your wallet must match the public address the currency is assigned to. If public and private keys match, the balance in your digital wallet will increase, and the senders will decrease accordingly. There is no actual exchange of real coins. The transaction is signified merely by a transaction record on the blockchain and a change in balance in your cryptocurrency wallet. Cryptocurrency Wallet Guide What are the different types of Cryptocurrencywallets? There are several types of wallets that provide different ways to store and access your digital currency. Wallets can be broken down into three distinct categories – software, hardware, and paper. Software wallets can be a desktop, mobile or online. Desktop: wallets are downloaded and installed on a PC or laptop. They are only accessible from the single computer in which they are downloaded. Desktop wallets offer one of the highest levels of security however if your computer is hacked or gets a virus there is the possibility that you may lose all your funds. Online: wallets run on the cloud and are accessible from any computing device in any location. While they are more convenient to access, online wallets store your private keys online and are controlled by a third party which makes them more vulnerable to hacking attacks and theft. Mobile: wallets run on an app on your phone and are useful because they can be used anywhere including retail stores. Mobile wallets are usually much smaller and simpler than desktop wallets because of the limited space available on a mobile. Hardware: wallets differ from software wallets in that they store a user’s private keys on a hardware device like a USB. Although hardware wallets make transactions online, they are stored offline which delivers increased security. Hardware wallets can be compatible with several web interfaces and can support different currencies; it just depends on which one you decide to use. What’s more, making a transaction is easy. Users simply plug in their device to any internet-enabled computer or device, enter a pin, send currency and confirm. Hardware wallets make it possible to easily transact while also keeping your money offline and away from danger. Paper: wallets are easy to use and provide a very high level of security. While the term paper wallet can simply refer to a physical copy or printout of your public and private keys, it can also refer to a piece of software that is used to securely generate a pair of keys which are then printed. Using a paper wallet is relatively straightforward. Transferring Bitcoin or any other currency to your paper wallet is accomplished by the transfer of funds from your software wallet to the public address shown on your paper wallet. Alternatively, if you want to withdraw or spend currency, all you need to do is transfer funds from your paper wallet to your software wallet. This process, often referred to as ‘sweeping,’ can either be done manually by entering your private keys or by scanning the QR code on the paper wallet.
Views: 10841 Blockgeeks
Real World Blockchain Applications - Real Estate
Real World Blockchain Applications - The Food Industry https://blockgeeks.com/ In the final part of our series, we go into the real estate market, and how many of it's inefficiencies can be solved by blockchain technology. We'll take a look at how smart contracts can make for a faster, easier, and more accessible real estate market. For more guides, training, and videos, visit us over at blockgeeks.com https://blockgeeks.com/guides/blockch... If you need a smart contract audited, or would like to become an auditor, check out our sister site at bountyone.io === According to a recent Deloitte report, Blockchain in Commercial Real Estate: The Future is Here, landlords, sellers and intermediaries (such as brokers and lawyers) all have access to the historical data for both the specific property alongside the commercial real estate market as a whole. No more entering data in multiple places, multiple times. "Today we can do all of those things with both websites and e-mails … but in a blockchain world, assuming that confidentiality is cleared, that property would have a property identity, so the previous people who owned the property, any of the inspections or records, landlord information, would be fully disclosed," explains Ms. Botting. "In theory, you're not involving a lot of paperwork and you're reducing the number of people involved in the process."
Views: 5504 Blockgeeks
What is Cryptocurrency? Easy To Understand Video
What is Cryptocurrency? https://blockgeeks.com/ A digital or virtual currency that uses cryptography for security. A cryptocurrency is difficult to counterfeit because of this security feature. Cryptocurrencies have skyrocketed in value over the last few years. Almost everyone has heard about Bitcoin, but how many people actually know what Bitcoin is? How many people know where they come from and how they work? This video will tell you everything you need to know about cryptocurrencies in an easy to understand format. Cryptocurrencies emerged as a side product of another invention. Satoshi Nakamoto, the unknown inventor of Bitcoin, the first and still most important cryptocurrency, never intended to invent a currency. In his announcement of Bitcoin in late 2008, Satoshi said he developed “A Peer-to-Peer Electronic Cash System.“ His goal was to invent something; many people failed to create before digital cash. Announcing the first release of Bitcoin, a new electronic cash system that uses a peer-to-peer network to prevent double-spending. It’s completely decentralized with no server or central authority. – Satoshi Nakamoto, 09 January 2009, announcing Bitcoin on SourceForge. The single most important part of Satoshi‘s invention was that he found a way to build a decentralized digital cash system. In the nineties, there have been many attempts to create digital money, but they all failed. … after more than a decade of failed Trusted Third Party based systems (Digicash, etc), they see it as a lost cause. I hope they can make the distinction, that this is the first time I know of that we’re trying a non-trust based system. – Satoshi Nakamoto in an E-Mail to Dustin Trammell After seeing all the centralized attempts fail, Satoshi tried to build a digital cash system without a central entity. Like a Peer-to-Peer network for file sharing. This decision became the birth of cryptocurrency. They are the missing piece Satoshi found to realize digital cash. The reason why is a bit technical and complex, but if you get it, you‘ll know more about cryptocurrencies than most people do. So, let‘s try to make it as easy as possible: To realize digital cash you need a payment network with accounts, balances, and transaction. That‘s easy to understand. One major problem every payment network has to solve is to prevent the so-called double spending: to prevent that one entity spends the same amount twice. Usually, this is done by a central server who keeps record about the balances. In a decentralized network, you don‘t have this server. So you need every single entity of the network to do this job. Every peer in the network needs to have a list with all transactions to check if future transactions are valid or an attempt to double spend. But how can these entities keep a consensus about this records? If the peers of the network disagree about only one single, minor balance, everything is broken. They need an absolute consensus. Usually, you take, again, a central authority to declare the correct state of balances. But how can you achieve consensus without a central authority? Nobody did know until Satoshi emerged out of nowhere. In fact, nobody believed it was even possible. For more blockchain guides, content, and videos, visit us at www.blockgeeks.com
Views: 53646 Blockgeeks
How to Become a Blockchain Developer
How to Become a Blockchain Developer https://blockgeeks.com/guides/blockchain-developer/ The fast growing world of blockchain is facing a huge shortage of talent. Many blockchain developers make nearly double what traditional developers make, but think it's too complicated to make the jump. In this video we'll outline some simple, basic steps you can take to start your journey into blockchain development. For more blockchain guides, courses, and videos, visit us at blockgeeks.com!
Views: 11086 Blockgeeks
How To Create An Ethereum Smart Contract
How To Create An Ethereum Smart Contract https://blockgeeks.com The most interesting part of Ethereum are smart contracts. You can think of smart contracts like autonomous agents deployed onto the Ethereum blockchain. Smart contracts are made up of some data, as well as some code that manipulates that data. Just like a user account, smart contract accounts also have their own balance as well as a public address, which looks the same as the user account address. To interact with smart contracts, you send transactions to it with some extra data, to specify which function you want to invoke, as well as any input parameters for the function. The transaction will invoke the function, and return any possible output once it has been mined. We're going to be using Remix to write smart contracts, which is an online IDE, available for free at remix.ethereum.org. It comes with a compiler, editor and debugger for solidity. The great part is that you don't need to download or install or set up anything, you just go to this webpage and start writing smart contracts, which is awesome. The UI is divided into four main sections. The left part is our file explorer where we can open Solidity files from our hard drive. The middle section is our editor where we can view and write our source code. At the bottom we have a terminal which prints out important events and transactions, and the rightmost section contains some handy tools for compiling running and debugging our code. The first example we'll look at is a smart contract called Hodor. Let's load up the source code. You'll notice that Solidity source files end with the .sol extension. The syntax of Solidity resembles java script, so it should be fairly easy to pick up. The first we see at the top uses the pragma directive. This tells the compiler that the contract is written for a Solidity compiler version of at least [0.4.0 00:01:53], or anything newer that doesn't break functionality. We then have a multi-line comment block, briefly describing what this class does. The next line is where we declare the name of our smart contract using the contract keyword. We've simply called out class Hodor because, as you'll see, all it does is return a simple greeting. We also declared two state variables called Creator and Greeting. Creator has an address data type, which is used for storing addresses of accounts. Greeting is a string data type, which just stores some text greeting. We initialized both of these variables in our constructor. The constructor is declared using the function keyword, followed by the name of the class. The constructor is a special function that is invoked only once, when a contract is first deployed to the Ethereum blockchain. You can only declare a single constructor for a contract. We also inject the initial string greeting as a parameter, into the constructor, and set the greeting variable to that value. In the second line of the constructor, we initialize the creator variable to a value called message.sender, but if you look closely, you might wonder where this value came from, since it's not being injected into the constructor. This is because message is a global variable that provides certain information about the message, such as the address of the account sending it. We can get the address of the account creating the contract, using message.sender in the constructor. You may notice that we don't actually use this creator variable anywhere in our contract, because this is just a simple example. We could potentially use this information to implement access control to certain functions. We'll see an example of this later. Read more on Blockgeeks: https://blockgeeks.com
Views: 49368 Blockgeeks
What is a Stablecoin? Most Comprehensive Video Guide
What is a Stablecoin? Most Comprehensive Video Guide https://www.blockgeeks.com “Stable coin” is a term used in cryptocurrency to describe cryptocurrencies meant to hold stable values. For example, Tether (USDT) is a blockchain based asset meant to trade for $1 USD. Tether is a “price-stable cryptocurrency” that is “pegged” to the U.S. dollar. https://blockgeeks.com/guides/tether/ There are a number of stable coins in circulation today, and a number more have been attempted in the past (with varying degrees of success). Each stable coin has a unique set of mechanisms, but they all generally work the same way: They hold collateral of some type and manage the supply to help incentivize the market to trade the coin for no more or less than $1. For some, like Tether or TrueUSD, the concept is to hold actual dollars in reserve that are redeemable for the token. For others, like Dai, they hold crypto assets in reserve and have a lending system.sing value due to price volatility—one of the reasons why cryptocurrencies haven't been widely adopted yet. The likes of bitcoin, Ethereum and Litecoin have been used severally for transactions involving online payments. They have, however, not been reliable for making day-to-day transfers due to high volatility in price.
Views: 11207 Blockgeeks
Real World Blockchain Applications - The Food Industry
Real World Blockchain Applications - The Food Industry https://blockgeeks.com/ There's a lot of talk about the mechanics and complexities of blockchain technology. Sure it's revolutionary, but why? What can it actually be used for besides cryptocurrency? In this four part series we're going to dive into some concrete use cases-- covering real world examples of how the blockchain is being used today. Let's discover together how the technology behind Bitcoin can be used to change the world. For more guides, training, and videos, visit us over at blockgeeks.com https://blockgeeks.com/guides/blockchain-applications-real-world/ If you need a smart contract audited, or would like to become an auditor, check out our sister site at bountyone.io
Views: 5082 Blockgeeks
What is Proof of Stake! Super Simple 1 Min Video!
What is Proof of Stake! Super Simple 1 Min Video! https://blockgeeks.com/guides/proof-of-work-vs-proof-of-stake/ You've heard of proof of work as a consensus method, but how about proof of stake? How does it work, and why is it beneficial? Join Jack as he describes the functions and pros of the proof of stake consensus method! For more information, check out www.blockgeeks.com Join our developer community at www.bountyone.io Keyword Validators: https://blockgeeks.com/guides/proof-of-work-vs-proof-of-stake/ === Proof of stake is a type of algorithm by which a cryptocurrency blockchain network aims to achieve distributed consensus. In PoS-based cryptocurrencies the creator of the next block is chosen via various combinations of random selection and wealth or age.
Views: 7644 Blockgeeks
Real World Blockchain Applications - Cybersecurity
Real World Blockchain Applications - Cybersecurity https://blockgeeks.com/guides/ In part two of our four-part series, we tackle some major issues in the world of cybersecurity, and how blockchain technology can help solve them. In this guide, we talk about the concepts of consensus and immutability. If you want to learn more, be sure to head over to blockgeeks.com where we have tons of guides, content, and videos. If you're a blockchain developer looking to earn crypto by auditing contracts, check out our sister site over at bountyone.io
Views: 3768 Blockgeeks
What is Bitcoin? The Most Comprehensive Guide Ever!
What is Bitcoin? https://blockgeeks.com/guides/what-is-bitcoin/ Bitcoin is the most well known and valuable cryptocurrency in the world. Ten years ago the original whitepaper was released online, and since then it's been an unstoppable movement worth over $90 billion U.S. dollars. But how does it actually work? How can someone have possibly just... created something with so much value? In this guide we'll go over all the basics of Bitcoin, from how it functions, to how to send it. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com! === At its simplest, Bitcoin is either virtual currency or reference to the technology. You can make transactions by check, wiring, or cash. You can also use Bitcoin (or BTC), where you refer the purchaser to your signature, which is a long line of security code encrypted with 16 distinct symbols. The purchaser decodes the code with his smartphone to get your cryptocurrency. Put another way; cryptocurrency is an exchange of digital information that allows you to buy or sell goods and services.The transaction gains its security and trust by running on a peer-to-peer computer network that is similar to Skype, or BitTorrent, a file-sharing system. What is Bitcoin? A Step-By-Step Guide For Beginners Buy Bitcoin here Bitcoin Transactional properties: 1.) Irreversible: After confirmation, a transaction can‘t be reversed. By nobody. And nobody means nobody. Not you, not your bank, not the president of the United States, not Satoshi, not your miner. Nobody. If you send money, you send it. Period. No one can help you, if you sent your funds to a scammer or if a hacker stole them from your computer. There is no safety net. 2.) Pseudonymous: Neither transactions or accounts are connected to real world identities. You receive Bitcoins on so-called addresses, which are randomly seeming chains of around 30 characters. While it is usually possible to analyze the transaction flow, it is not necessarily possible to connect the real world identity of users with those addresses. 3.) Fast and global: Transaction is propagated nearly instantly in the network and are confirmed in a couple of minutes. Since they happen in a global network of computers they are completely indifferent of your physical location. It doesn‘t matter if I send Bitcoin to my neighbour or to someone on the other side of the world. 4.) Secure: Bitcoin funds are locked in a public key cryptography system. Only the owner of the private key can send cryptocurrency. Strong cryptography and the magic of big numbers makes it impossible to break this scheme. A Bitcoin address is more secure than Fort Knox. 5.) Permissionless: You don‘t have to ask anybody to use cryptocurrency. It‘s just a software that everybody can download for free. After you installed it, you can receive and send Bitcoins or other cryptocurrencies. No one can prevent you. There is no gatekeeper.
Views: 16773 Blockgeeks
What are Atomic Swaps?
What are Atomic Swaps? https://blockgeeks.com/guides/atomic-swaps/ Atomic Swaps are an emerging piece of blockchain technology that can help users make peer-to-peer coin trades without any intermediaries! In this guide we cover how they work, and how they benefit you, the user! For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 5336 Blockgeeks
Real World Blockchain Applications - Healthcare
Real World Blockchain Applications - Healthcare https://blockgeeks.com/guides/blockchain-in-healthcare/ Originally, we wrapped up our Real World Blockchain series a few months ago. But we later realized that there was a huge industry we missed out on that could really use what the blockchain has to offer. That industry is healthcare. In this guide we talk about some of the problems in healthcare, specifically in data management, and then delve into how blockchain technology can solve them. Check out the rest of our Real World Blockchain series to learn more, and see more blockchains in action! https://www.youtube.com/playlist?list=PLy_eQQ6VGZFxiYp89IE19c7Q_ulN3Enzq For more blockchain guides, videos, and courses, visit us at https://blockgeeks.com/
Views: 5703 Blockgeeks
What is a Bitcoin Node? - Step by Step Explanation
What is A Bitcoin Node. Step by Step Explanation https://blockgeeks.com/ The bitcoin network consists of a network of nodes, which are just computers or servers running the Bitcoin software. The code ensures the nodes can find and establish connection with other nodes and hence form a network that is used by the various nodes to transfer information, like transactions, blocks and other data. Through this web of interconnecting nodes, bitcoin can send digital cash securely through the network. The underlying bitcoin code implements the bitcoin protocol. So how does a new node join the bitcoin network? First it must discover at least one peer to connect to and then it can get a list of other peers from that initial peer. There are a few methods a node can use to connect to its first peer. The bitcoin client contains a hardcoded list of well known DNS servers which can return a list of ip addresses of bitcoin nodes. Alternatively, the bitcoin client can be given a static ip address of a peer if one is known. You can pass this ip address as a parameter when starting the bitcoin client software through the command line. It’s important to note that bitcoin’s network topology is not geographically defined, so the physical location of the nodes in relation to one another is irrelevant.This means a node can find and connect to any other node regardless of where it is in the world. Once a node has the ip address of a peer, it then goes through an initial handshake to establish a connection with a remote node. First the local node will send a version message to the peer which contains some basic information about itself. This will always be the first message sent by any peer to another peer. The remote peer receiving the message will examine if the sender’s version is compatible with its own version. If it is, it will acknowledge the version message and establish a connection by sending a “version acknowledgment” message, which consists only of a message header with the command string “verack”. Once a node establishes connections with one or more peers, it will exchange some information with these peers. For example, nodes can exchange ip addr of their connected peers, so each node can maintain a list of peers that it can use to re-establish connection in the future since nodes can leave and join the network at anytime. A Node can also ask its peers what the length of their local copy of the blockchain is. It can then determine if it’s own copy of the blockchain is missing any blocks, and if so, can ask its peers to send the missing blocks. Of course it can also send blocks to other nodes who do not have as much data as itself. Let’s take a closer look at the various nodes in the network. Although all the nodes participate in the network, they have different roles depending on the functionalities they want to support. There are 4 major functions: routing, storage, mining and wallet services. The bitcoin core client implementation in c++ has all four of these functionalities. Routing is the bare minimum functionality a node must support in order to participate in the bitcoin network. It contains the functionality to discover and connect to other peers in the network and it also validates and propagates transactions and blocks through the network. It serves the purpose of keeping the network connection alive and passing information through the network. A node is called a full blockchain node if it stores a local copy of the entire blockchain database. A full node can autonomously and authoritatively verify any transactions without any external references. With a full node you get complete independence and freedom from central authority at the cost of hardware storage space. A mining node serve the special purpose of creating a new block to add to the blockchain. Mining nodes runs special mining software in order to solve a cryptographic puzzle to win mining rewards. They serve the purpose of adding new transactions into the blockchain. To learn more visit us at blockgeeks.com
Views: 5672 Blockgeeks
Intro to Ethereum Dapps
Intro to Etheruem Dapps https://blockgeeks.com/ In this lesson, we’ll learn about building decentralized applications, or dapps. But first, let’s take a minute to appreciate the difference between dapps and regular web applications In traditional web application architecture, there is a frontend client and a backend server. The frontend is written using HTML/CSS/JS and the backend is written in a framework of your choice like Rails, Node or Django. The front and backend interact with each other by sending JSON messages over HTTP. There is typically a hosting service where your backend would be running like AWS. With decentralized applications, there is also a frontend client and a backend server. The frontend is written using the same HTML/CSS/JS, but for the backend we use a blockchain like Ethereum. The front and backend would still be interacting with each other using JSON messages. This architecture is a bit oversimplified, but the point is that the end-user will not be able to tell whether they are interacting with a dapp or any other regular web app; the change would be invisible and in the background. The traditional client-server architecture is so common that its rarely revisited. Should we still be building apps this way knowing everything we know now? Let’s take a look at some of the issues with the traditional client-server architecture. The first issue is that your server is running on a centralized hosting service who you outsource your hosting needs to. As more and more people around the world use the same popular hosting service, it becomes a single point of failure for the entire internet. Think about it: to take down all the sites that are running their backend on this popular hosting service, all you would have to do is disrupt this one provider’s infrastructure, in order to take down potentially half the internet! This isn’t a very resilient architecture for the web. It’s also an increasing amount of pressure on a single organization to expect them to build and maintain all this infrastructure for the entire world. Centralized servers are also easy to censor and control. Taking down a web application is as simple as removing it from the centralized server. This can happen at the state level where government agencies request hosting providers to take down certain websites they may not like or agree with. But if your application was running everywhere, taking it down would not be as straightforward. To censor a blockchain application, you would have to takedown all the network nodes simultaneously. The Ethereum blockchain currently has over 25,000 nodes spread around the world. When we increasingly rely on centralized services, we create honeypots of data for attackers. We have seen this time and time again with various hacks, the most recent being the Equifax hack. Equifax is a centralized credit reporting service, and they were responsible for maintaining millions of user’s personal credit information including social security numbers. Millions of people put their trust in this one organization to keep their data safe from getting into the wrong hands. As a potential attacker, its very lucrative to hit just one database and get access to millions of people’s sensitive data that you could then use to open credit cards for example. With a decentralized database like a blockchain, data attacks are not as trivial as getting access to a single database. Another issue with the traditional client-server architecture is that of data integrity. Along with your backend server, the database powering your application is also likely running on the same hosting service. Assuming you trust your hosting provider 100%, this isn’t an issue. But how can you be sure? What’s stopping an unauthorized employee at the hosting service from making changes to the data in your database? And what if your database contained people’s sensitive information, like bank account balances? That’s an awful lot of trust to put into any single organization with the most valuable part of your application: your data. In fact, data is so valuable that many companies are built on the very premise of selling your data. They do this by creating a centralized website for users to interact with, by either posting photos or entering search words. They record your interactions to a database, and then sell your interaction data to advertisers for lots of money without your knowledge or consent. Think about that: all the data that is generated by everyone in the world is monetized by only a handful of companies. With decentralized applications, users can regain control of their data and decide for themselves whether to monetize it by choosing to sell to advertisers or not. And they get to keep the money, not some other company. For more check out https://blockgeeks.com/
Views: 32265 Blockgeeks
What is Blockchain Technology? Easy To Understand Video
What is Blockchain Technology? https://www.blockgeeks.com Join us for an easy to understand and simple breakdown of blockchain technology. We'll introduce you to all the basic concepts so you can begin your journey into the world of blockchain and cryptocurrencies. Stay tuned for our simple blockchain guides being released every Monday! For more guides, content, and videos, check us out over at blockgeeks.com! If you're already a blockchain developer and need a smart contract audited, visit our sister site https://www.bountyone.io How Does Blockchain Work? Picture a spreadsheet that is duplicated thousands of times across a network of computers. Then imagine that this network is designed to regularly update this spreadsheet and you have a basic understanding of the blockchain. Information held on a blockchain exists as a shared — and continually reconciled — database. This is a way of using the network that has obvious benefits. The blockchain database isn’t stored in any single location, meaning the records it keeps are truly public and easily verifiable. No centralized version of this information exists for a hacker to corrupt. Hosted by millions of computers simultaneously, its data is accessible to anyone on the internet. To go in deeper with the Google spreadsheet analogy, I would like you to read this piece from a blockchain specialist. Blockchain as Google Docs https://blockgeeks.com/guides/what-is-blockchain-technology/
Views: 124612 Blockgeeks
What is an STO? Security Token Offering
What is an STO? https://blockgeeks.com/guides/security-tokens-explained/ In many ways, security tokens are the antithesis of initial coin offerings. They are regulated, structured, and can sometimes be costly to create. While these might seem like drawbacks to some, they provide big benefits to investors, as well as the project leads. In this guide we go over the difference between STOs and ICOs, as well as their core systems and benefits. == A crypto token that passes the Howey Test is deemed a security token. These usually derive their value from an external, tradable asset. Because the tokens are deemed a security, they are subject to federal securities and regulations. If the ICO doesn’t follow the regulations, then they could be subject to penalties. However, if all the regulations are properly met, then these tokens have immensely powerful use-cases. For more videos, courses, and guides, visit us over at https://blockgeeks.com!
Views: 2316 Blockgeeks
Parity Wallet Hack Explained
Parity Wallet Hack Explained https://blockgeeks.com We’re going to do a security case study using a recent vulnerability found in a wallet smart contract deployed by Parity Technologies. Parity is a key infrastructure developer in the Ethereum ecosystem, including essential libraries like web3js. The purpose of this lesson isn’t to point fingers, but to learn from real-world security issues for the betterment of the community. It wasn’t a vulnerability in the Ethereum protocol itself that was exploited, but the code deployed in a particular wallet smart contract. Let’s first understand what a wallet contract is. It stores money, like a regular user account, so whats the difference? The difference is that a wallet is a Solidity smart contract, while a user account is just a user account. You can think of a wallet as adding logic on top of a user account to create features like daily spending limits or multi-signature withdrawals. Multi-signatures wallets are like regular wallets in that they are also smart contracts, but they require multiple approvals to withdraw any amount out of the wallet. So you could deploy a multisignature wallet contract with 3 people, and set a rule that you need at least 2 of the 3 to approve any withdrawals from the wallet. Or however many approvals you want. You could even use it for multi-factor authentication for your own wallet, to ensure that if you ever lost one of your keys, your funds wouldn’t be completely lost. Now let’s take a look at the multi-signature wallet contract from Parity that was exploited. We’re not going to walkthrough the entire code, but we will look at the exploited code. The lines we’re interested in are here. The initWallet function is called when constructing a new wallet to setup its initial state. And the kill function right below is essentially a call to self-destruct. Every multi-signature Parity wallet deployed by users since July 20th 2017 relied on this library contract for its functionality. A library contract is just a smart contract, but it’s used to achieve better gas management. Let’s say you have a really awesome Solidity string library containing hundreds of convenience functions on strings that you share on your Github. Others can download your source code, use it in their own projects, and then deploy it alongside their own contracts. But the more EVM byte code a contract has to deploy, the more gas is needed for the deployment transaction. And this gas fee would be incurred by every single person deploying your code. A more gas-efficient approach would be to deploy your code as a library contract to the blockchain, where others can then invoke it from their own contracts without having to download and deploy a copy of your code. The gas fee for the library contract would only have to be paid once by you, instead of by every single user of your code. The obvious downside of doing this is that everyone else’s contract would be dependent on your library contract instance, creating a potential single point of failure. So there are serious tradeoffs for bringing this type of centralization to a decentralized computing environment. Parity used a library contract to deploy the common logic for their multi-signature wallets, such as being able to withdraw funds from your wallet. This library contract had been deployed and in use since July 20th 2017, but just last week on November 6th, an anonymous user was able to gain control of this library contract. The cool thing about the blockchain is that all interactions are recorded to a globally readable database. So we can actually go back and see the transactions in which the attacker exploited the library contract. We know the address of the library contract from Parity’s website, so let’s go over to etherscan and take a look at it. Read more on Blockgeeks: https://blockgeeks.com
Views: 6476 Blockgeeks
What is Hashing on the Blockchain?
What is Hashing on the Blockchain? https://blockgeeks.com/guides/what-is-hashing/ Cryptographic hashing is a key feature in the security and efficiency of blockchains. If you've ever wondered how so much data can be stored securely on every node in the network, hashing is a big part of the answer! We'll cover all the basics you need to know in this video! For more blockchain guides, courses, and videos, visit us at blockgeeks.com! Cryptographic hash functions A cryptographic hash function is a special class of hash functions which has various properties making it ideal for cryptography. There are certain properties that a cryptographic hash function needs to have in order to be considered secure. Let’s run through them one by one. Property 1: Deterministic This means that no matter how many times you parse through a particular input through a hash function you will always get the same result. This is critical because if you get different hashes every single time it will be impossible to keep track of the input. Property 2: Quick Computation The hash function should be capable of returning the hash of an input quickly. If the process isn’t fast enough then the system simply won’t be efficient. Property 3: Pre-Image Resistance What pre-image resistance states is that given H(A) it is infeasible to determine A, where A is the input and H(A) is the output hash. Notice the use of the word “infeasible” instead of “impossible”. We already know that it is not impossible to determine the original input from its hash value. Let’s take an example. Suppose you are rolling a dice and the output is the hash of the number that comes up from the dice. How will you be able to determine what the original number was? It’s simple all that you have to do is to find out the hashes of all numbers from 1-6 and compare. Since hash functions are deterministic, the hash of a particular input will always be the same, so you can simply compare the hashes and find out the original input. But this only works when the given amount of data is very less. What happens when you have a huge amount of data? Suppose you are dealing with a 128-bit hash. The only method that you have to find the original input is by using the “brute-force method”. Brute-force method basically means that you have to pick up a random input, hash it and then compare the output with the target hash and repeat until you find a match.
Views: 7839 Blockgeeks
What is an ERC-721 Token?
What is an ERC-721 Token? https://blockgeeks.com/guides/erc-721-cryptokitty-token/ ERC-721 tokens are the technological backbone of the ever popular Cryptokitties. So what are these tokens? And how do they enable a whole new world of digital collectibles? In this guide we'll talk about what gives these tokens value, and how the blockchain can create truly unique virtual assets. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com! === ERC-721 The ERC-721 token standard helps create non-fungible tokens. In many ways, it is pretty similar to ERC-20 in functionality. This similarity exists for two reasons: Firstly, it is easier for developers to make the transition. Since all ethereum developers are familiar with ERC-20 already, they won’t have to learn a host of new things It makes life much easier for users who can store these tokens in ordinary wallets and trade them on exchanges. ERC-721 gains its non-fungible properties by capturing the ownership of that particular token. This is why takeOwnership functions are included in the ERC-721 standard. ERC-721 Functions The ERC-721 standard defines the following functions: name, symbol, totalSupply, balanceOf, ownerOf, approve, takeOwnership, transfer, tokenOfOwnerByIndex, and tokenMetadata. It also defines two events: Transfer and Approval. Before we go into individual function discussions, you must know what we mean by the Token Ownership and Token Creation of the ERC-721 functions Token Ownership When you buy ERC-20 tokens, your rights of ownership will be written in the smart contracts. The smart contract also has data of how much tokens each and every address will have after the deal…and that’s it. The thing is that these contracts don’t need to worry about specific tokens because they are fungible, so they are all the same. However, the value of one ERC-721 token is not the same as another ERC-721 token because of its non-fungibility. Adding an address and balance to the contract won’t be enough, a token’s unique ownership details also need to be added. Token Creation Token Creation in ERC-20 tokens is about the balance of tokens. So, all that you need to do is to set an upper limit and make sure that people cannot create more tokens than the upper limit. When compared to that, ERC-721 token creation is much more complicated. The ERC-721 standard maintains an array of tokens and each and every single token is added to the array separately.
Views: 4697 Blockgeeks
The History of Ethereum
The History of Ethereum - https://www.blockgeeks.com After Satoshi released Bitcoin to the world in 2008, a community of blockchain developers and researchers started to take shape around it. Many developers contributed to the open-source development of Bitcoin. Several magazines and online blogs also started to appear, writing about interesting projects and new ideas in the space. One of the members of this community was a Canadian teenager named Vitalik Buterin who worked as a writer for a publication called Bitcoin Magazine. As he was watching the ecosystem take shape, he noticed a common problem among projects: that many of them needed to start their own blockchain. This got Vitalik wondering: wouldn’t it be nice to have one single blockchain that everyone could build their applications on, just like we have one single internet that everyone can build their websites on. Instead of figuring out how to start a blockchain, developers would then be able to focus on building their own applications. So in late 2013, Vitalik published the Ethereum whitepaper which built on many concepts from Bitcoin. The whitepaper is available today on the Ethereum Github page. In the paper, he outlined the limitations of the Bitcoin blockchain and proposed a new general-purpose blockchain that could be used as a decentralized application platform. Ethereum would be able to do everything Bitcoin could, like sending transactions between accounts, and a whole lot more. The main issue with Bitcoin was the lack of a general-purpose programming language that would allow you to create any sort of application on top of its blockchain. Bitcoin scripts are not Turing-complete, meaning you cant write simple structures like loops, and they are also limited in capability because they cant store state. These scripts are also referred to as simple versions of smart contracts. The Ethereum whitepaper described its own native currency called ether and a new runtime environment for smart contracts, called the Ethereum Virtual Machine, or EVM. A subsequent yellowpaper was released in mid-2014 by collaborator Gavin Wood that would define the technical specification of the EVM and how it would work. The yellowpaper was used to create several open-source implementations in different languages, the most popular one being the Go language client, also known as geth. The second most popular implementation was written in the Rust language and is called the Parity client. Anyone running a client is a node in the Ethereum network, which currently has over 25 thousand nodes around the world. Smart contracts are just application logic that can be expressed using the operations defined in the EVM, and they can also store data on the blockchain. EVM opcodes are low-level machine language which isn’t very human-readable, so developers write smart contracts in high-level languages that compile down to EVM opcodes. Several high-level languages exist like Serpent and Viper, but the most popular one today is called Solidity and it has a syntax similar to Javascript. Smart contracts can contain some data as well as code that manipulates that data. You can think of a smart contract like a class that has fields and methods. Anyone can use Solidity to write a smart contract and deploy it to the Ethereum blockchain using a simple transaction. You would do this by compiling your Solidity smart contract down to EVM bytecode, and then sending the bytecode as part of a transaction to the Ethereum network. Once the transaction gets mined, the smart contract is deployed to the blockchain and given a public address. Anyone can then interact with the smart contract by sending transactions to its address and specifying which method they want to invoke. The result of the method call is written to the blockchain after the transaction is mined. There is also a cost associated with invoking a smart contract method called gas. Gas is just a unit of measurement that determines how much computation an EVM opcode requires. The price of one unit of gas is set in ether, and is known as the gas price. The gas price is used to calculate the total transaction fee for invoking a method call based on how much gas it requires, and it must be paid by the sender of the transaction. An interesting thing to note is that any transaction that invokes a smart contract method gets executed on every single Ethereum node. This means that in order to mine a transaction into a block, you have to invoke any smart contract methods for it as well. In this sense, Ethereum can be thought of as a decentralized world computer where you pay for computation using ether. To read more, be sure to visit us at www.blockgeeks.com
Views: 4633 Blockgeeks
What is an ICO?
What is an ICO? https://blockgeeks.com/guides/initial-coin-offering/ What is An Initial Coin Offering? ICOs are basically blockchain crowdsales, the cryptocurrency version of crowdfunding. The ICOs have been truly revolutionary and have managed to accomplish many amazing tasks: They have provided the simplest path by which DAPP developers can get the required funding for their project. Anyone can become invested in a project they are interested in by purchasing the tokens of that particular DAPP and become a part of the project themselves. It was in July 2014 when ICOs well and truly came into the public’s attention. That was when the ICO Ethereum raised $18.4 million and ushered in a new age of ICOs. Since 2013 ICOs are often used to fund the development of new cryptocurrencies. The pre-created token can be easily sold and traded on all cryptocurrency exchanges if there is demand for them. With the success of Ethereum, ICOs have become the de-facto method of funding the development of a crypto project by releasing a token which is somehow integrated into the project. Short History of Initial Coin Offering Maybe the first cryptocurrency distributed by an ICO was Ripple. In early 2013 Ripple Labs started to develop the Ripple called payment system and created around 100 billion XRP token. The company sold these token to fund the development of the Ripple platform. Later in 2013, Mastercoin promised to create a layer on top of Bitcoin to execute smart contracts and tokenize Bitcoin transactions. The developer sold some million Mastercoin token against Bitcoin and received around $1mio. Several other cryptocurrencies have been funded with ICO, for example, Lisk, which sold its coins for around $5mio in early 2016. Most prominent however is Ethereum. In mid-2014 the Ethereum Foundation sold ETH against 0.0005 Bitcoin each. With this, they receive nearly $20mio, which has become one of the largest crowdfunding ever and serves as the capital base for the development of Ethereum. As Ethereum itself unleashed the power of smart contracts, it opened the door for a new generation of Initial Coin Offering. Ethereum – The Initial Coin Offering? ICO Crowdfunding Machine One of the easiest application of Ethereum’s smart contract system is to create a simple token which can be transacted on the Ethereum blockchain instead of Ether. This kind of contract was standardized with ERC#20. It made Ethereum host of such a wide scope of ICO that you can safely say that Ethereum found its Killer App as a distributed platform for crowdfunding and fundraising. What is An Initial Coin Offering? The Future of Fundraising (ICO) The most prominent demonstration of the potential of Ethereum’s smart contracts has been The DAO. The distributed investment company was fuelled with Ether worth $100m. The investors received in exchange against Ether Dao Token which had their own market price and enabled the holder to participate in the governance of the DAO. After it was hacked, the DAO however failed. The concept of funding projects with a token on Ethereum became the blueprint for a new and highly successful generation of crowdfunding projects. If you already tried out, you know that investing in token on top of Ethereum is charmingly easy: You transfer ETH, paste the contract in your wallet – and, tata: The token appear in your account and you are free to transfer them as you want. Before we go any further, let’s understand what tokens mean. Tokens = ICO Cryptocurrency? For more videos, courses, and guides, visit us over at https://blockgeeks.com!
Views: 3260 Blockgeeks
What is the ERC-1155 Token Standard?
What is the ERC-1155 Token Standard? https://blockgeeks.com/erc-1155-token/ You've heard of ERC-20 and ERC-721, and you may even own some! They seem to work pretty well, right? So what's the use of this shiny new ERC-1155 standard? It combines the two into one, efficient contract. In this guide, we go over a couple of simple use cases for ERC-1155 tokens, and talk about why it's a good idea for developers and users. For more videos, courses, and guides, visit us over at https://blockgeeks.com!
Views: 2342 Blockgeeks
Exploring Enterprise Blockchain Solutions
Exploring Enterprise Blockchain Solutions https://blockgeeks.com/guides/enterprise-blockchains/ Lots of us know about the success and benefits of public blockchains like Bitcoin and Ethereum. But do blockchains work in a private setting for business and enterprise? Absolutely! In this guide we go over some of the key benefits you gain from bringing blockchain solutions into your business, as well as cover some real world companies that are already doing it! For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 4983 Blockgeeks
Vitalik Buterin Interview - EDCON 2018
Our instructor Haseeb got the chance to interview Ethereum Co-Founder Vitalik Buterin! Watch as they discuss sharding, sports, and fortnite! http://www.blockgeeks.com
Views: 4822 Blockgeeks
What is a Decentralized Exchange and Why Should You Care?
What is a Decentralized Exchange and Why Should You Care? https://blockgeeks.com/guides/decentralized-exchanges/ Decentralized exchanges are a huge part of ensuring that everyone is able to access cryptocurrency networks, regardless of who they are or where they live. While centralized exchanges gate access to the blockchain, while decentralized exchanges do not and can not. In this guide, we'll talk about how they work, and what some of their benefits are. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 4873 Blockgeeks
What is Sharding? Super Simple 1 Min Video
What is Sharding? Super Simple 1 Min Video https://blockgeeks.com/guides/what-are-ethereum-nodes-and-sharding/ Sharding is just one of the many blockchain scaling solutions being developed and theorized today. But how does it all work? How could it help the blockchain be more efficient? Niloo gives you the low down in just 60 seconds. For more blockchain content, courses, and education, visit us over at blockgeeks.com. If you're a developer looking for freelance opportunities and hackathons, check out our sister site bountyone.io! === Any computer, connected to the Ethereum network, which fully enforces all the consensus rules of Ethereum is called a Full Node. A full node downloads the entire blockchain in the user's desktop. Full nodes form the backbone of the Ethereum system and keep the entire network honest
Views: 1519 Blockgeeks
How to Write an Ethereum Election Smart Contract
How to Write an Ethereum Election Smart Contract https://blockgeeks.com In this video we are going to learn how to code up an election contract. We want to hold a free and fair election for a specified amount of time and only allow authorized people to vote in it We’ll start by defining a custom data type called a struct, which allows us to group together other data types, to define a Candidate struct. For a candidate in the election, we’ll keep track of their name and the number of votes they currently have. Let’s also define a struct for the Voter, that will store whether or not the voter has already voted, and who they voted for. We need to keep track of the owner of the contract as they will have special rights to authorize voters. We also keep a mapping to store voter information, as well as a dynamically-sized array of candidates that will be initialized on construction. The way to define an array is to simply use the square brackets after the data type of a variable. We’ll also keep track of the time when the election ends using an integer timestamp. We’ll initialize our list of candidates in the constructor. We pass in a name for our election, the duration of the election in minutes, and an array of candidate names. But wait, when we try to pass in a string array, we get a compiler error saying ‘nested arrays not yet implemented’. Why is that? This is because functions in Solidity cannot accept or return 2-dimensional arrays. but you might say hey we’re not actually using a 2-dimensional array here we’re just using a 1-dimensional array of strings. And even though it appears that way, under the hood, the string data type is implemented as an array of the bytes32 data type. So when we add the square brackets after string, its actually a 2d array of bytes32, which is not yet supported. As a workaround for now, we’ll just pass in 2 string arguments representing only two candidates in the election. If we wanted to support multiple candidates, we could just pass in an array of bytes32. We’ll define candidate objects using the provided names We also set our auctionEnd variable to be from now plus the specified duration in minutes. Now is a global variable, which is an alias to another global variable called block.timestamp. It returns a unix timestamp indicating the current block’s creation time, not the actual current time. Solidity also supports many time units such as minute, days, months. For now we’ll just use minutes. We’ll define an authorize function that allows the owner of the contract to give voting rights to any address. In this function, we initialize the Voter object for the address. Even though this looks like we are initializing an object in the voters mapping, that’s not actually what’s happening. Mappings can be thought of as hash tables which are virtually initialized such that every possible key exists and is mapped to a value whose byte-representation is all zeros, which is a type’s default value. So for bool it would be false, and for integer it would be 0. So when we initialize this Voter struct with false and 0, we’re not actually doing anything since these are already the default values set in the mapping. The implication being that anybody would be able to participate in the election, not just the authorized voters, and thats not quite what we want. To solve this, we’ll add a weight field to the Voter struct which will specify the weight of a vote. This will allow us to only count votes from people we authorize with a weight of 1. So to give voting rights, we don’t need to create a Voter struct and pass in all the fields, we just need to set the one field that won’t default to 0, in this case we set the weight for the voter to 1. Read more on Blockgeeks: https://blockgeeks.com
Views: 10384 Blockgeeks
What is a Dapp?
What is a Dapp? https://blockgeeks.com/guides/dapps/ Many businesses are built around the idea of centralization. They facilitate safe and speedy transactions in exchange for a portion of the transaction. But what if that wasn't necessary any more? Bitcoin has proven that no authority is needed to facilitate transactions. Decentralized applications will soon be able to do everything that centralized ones can, so what does that mean for the businesses that exist solely to take a cut of a transaction? In this video, we explain what a Dapp is, and what they mean for the future. For more blockchain guides, courses, and videos, visit us at blockgeeks.com! ==== What are Dapps you might ask? Imagine having your car working away, transporting passengers while you’re at work. Imagine having your computer utilizing its spare capacity to serve businesses and people across the globe. Imagine being paid for browsing the web and taking ownership of your, arguably invaluable, attention. Imagine a world like that. That world is not far away. A paradigm shift in the way we view software models is approaching. When Bitcoin, the first cryptocurrency, made us reassess our definition of Store of Value (SoV), it also revealed a sneak peek of the future: a world running on decentralized applications (Dapps). These distributed, resilient, transparent and incentivized applications will prove themselves to the world by remapping the technological landscape.
Views: 14243 Blockgeeks
What Is Rootstock?
Join Niloo as she talks us through the Rootstock platform, explains sidechains, and tells us about Smart Bitcoin! If you're interested in learning more about Rootstock, check out www.blockgeeks.com where we have a full course taking you from environment setup to deploying your first smart contract! If you want to participate in a hackathon, or if you want to become a smart contract auditor, visit www.bountyone.io for more information!
Views: 4793 Blockgeeks
Decentralized Storage Explained
Decentralized Storage Explained - https://blockgeeks.com/ In this lesson we’ll learn about decentralized storage and some services that are available today like IPFS and Swarm. You can think of decentralized storage as a peer-to-peer network where members pool together their disk space to create a shared global memory, kind of like Dropbox but decentralized. Both IPFS and Swarm are similar in that they are opensource decentralized storage solutions, but they differ in implementation and approach. IPFS, which stands for interplanetary file system, is a protocol that was published by an organization called Protocol Labs. The first implementation of the IPFS protocol was written in the Go language and published in early 2015, and today there are several alpha release implementations available including in javascript. Swarm is also a protocol, and is part of the Ethereum holy trinity that makes up the serverless world computer, which consists of Swarm, Ethereum and Whisper. These three infrastructure projects are part of a broader vision that provides a completely decentralized alternative to the currently centralized web. Ethereum would provide the computation power; Swarm would provide the storage layer; And Whisper would provide a messaging layer. Swarm and Whisper are not quite as far along in their roadmaps as Ethereum. But a proof-of-concept Swarm implementation written in the Go language is included as part of the geth client since version 1.5 You may have noticed I said that both projects are either in alpha or proof-of-concept stages, meaning theyre not quite yet ready for the production spotlight. But understanding the role of decentralized storage in the future web is important, so you should know how to make use of these tools. As these projects evolve and mature, they will become increasingly production ready. Let’s start by looking at how to use Swarm. Since Swarm is already part of the Ethereum stack, a proof-of-concept Go language implementation exists as part of geth. So to activate swarm, we need to download and build geth and swarm from source. To do this, we need to have Git and Go installed in our environment. You can do this easily using the command brew install go git. Then you need to make sure your Go environment is setup correctly. You can do this by creating a folder called go in your home folder, and then exporting an environment variable called $GOPATH which points to this folder. We’ll then install from source by downloading the go-ethereum source code from their github mkdir -p $GOPATH/src/github.com/ethereum cd $GOPATH/src/github.com/ethereum git clone https://github.com/ethereum/go-ethereum cd go-ethereum git checkout master go get github.com/ethereum/go-ethereum And now we can compile geth and swarm from source: go install -v ./cmd/geth go install -v ./cmd/swarm We’re now ready to run the swarm daemon by using the binary in our $GOPATH. You can add this bin folder to your PATH for convenience. If you run swarm version, we can see that we are on version 1.8. To use Swarm, you need to have an Ethereum account. You can do this quickly using geth account new. After entering a password, this will print out the new account address that we will use to join the Swarm network. You can copy the public address to your clipboard. To run Swarm we first need to make sure we have geth running. Then in a separate tab we run swarm and point it to our Ethereum account using the —bzzaccount option and pasting in our public address. It will prompt for your password to unlock the keyfile for Swarm, and then start up a local Swarm node on port 8500. Now we can easily upload files using swarm command line tools by simply calling swarm up followed by the path of the file you want to upload. Swarm doesn’t support encryption yet, so make sure you dont upload any sensitive files. After uploading, you’ll get a unique hash printed out for this file that points to it on the Swarm network. Let’s upload our index.html from our previous blockchain explorer example. To read more check out https://blockgeeks.com/
Views: 9564 Blockgeeks
Ethereum is Hard Forking! Learn About the Constantinople Upgrade
Ethereum is Hard Forking! Learn About the Constantinople Upgrade https://blockgeeks.com/guides/ethereum-constantinople-hard-fork/ The Ethereum network is upgrading! The Constantinople hard fork is coming near the end of February, and it's bringing a few changes to the network. In this guide, we go over what you need to know about forks, and what's in store when Constantinople goes live. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 6630 Blockgeeks
The Five Biggest Cryptocurrency Hacks and What We Can Learn From Them
The Five Biggest Cryptocurrency Hacks and What We Can Learn From Them https://blockgeeks.com/guides/cryptocurrency-hacks/ The blockchain is undoubtedly one of the most secure digital platforms ever created, but that doesn't mean it's perfect. In this video we overview five of the biggest cryptocurrency hacks. Education makes for a stronger and safer community, so we'll talk about how they happened, and what can be done to prevent similar attacks in the future. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com!
Views: 3402 Blockgeeks
What is The History of Bitcoin: Super Easy Explanation
What is The History of Bitcoin: Super Easy Explanation - https://blockgeeks.com/ We’ll start at the very beginning by understanding the history of blockchain. The very first blockchain in the world was Bitcoin. An anonymous person or group known as Satoshi Nakamoto published a document in an online cryptography forum in November 2008 and revealed the first details of how it would work, describing it as a “peer-to-peer electronic cash system”. The whitepaper is available today at bitcoin.org/bitcoin.pdf. It allows any 2 people to pseudonymously send money to each other no matter where they are in the world. It is a borderless currency. The main benefit of Bitcoin is that it does not require any centralized authority or institution to operate. This is in contrast to today’s centralized financial systems that depend on the existence of a central bank or government to mint money. If for any reason the central authority were to shutdown, the money would become worthless. In a decentralized system like Bitcoin, there is no central authority and the system can continue to operate as long as there are members in its peer-to-peer network. The goal of the whitepaper was to describe how the different parts of the Bitcoin protocol would operate and be kept secure. A new type of database, called a blockchain, would keep track of a single history of all Bitcoin transactions and it would be maintained by everyone in the network. The database would be publicly available for anyone to view and inspect, and anyone can download a copy of the same database. This provides data redundancy and makes sure the data is never lost, but also provides a way for anyone to verify the transactions in the database themselves. A block in the database just stores a sequence of transactions, and a sequence of blocks is called a blockchain. Each block is identified by an incrementing number and a unique Sha-256 hash. The hash for a block is calculated using the transactions inside it, as well as the previous block’s hash, which forms a chain of hashes. The data in the blocks is secured using a cryptographic algorithm called proof-of-work, which also keeps all members of the network and the database in sync to prevent double-spending. In this context, preventing double-spending means preventing anyone from spending money they dont have. Proof-of-work is used to generate new blocks for the database, also known as mining, and the reward for mining a new block is given to the miner by creating new Bitcoins in the system. This is the only way new Bitcoins can be created. Anyone on the network can be a miner and a new block is mined roughly every 10 minutes, which includes the latest set of verified transactions. The first release for Bitcoin was version 0.1 written in C++ by Satoshi and published on SourceForge in January 2009 under the open-source MIT license. Anyone could download the source code and run it to join the network, also known as becoming a node in the network. This is the original version 0.1 source code written by Satoshi. We can see the hard-coded genesis block, which is the very first block in the chain. The hash for the block can be verified by using any Bitcoin blockchain explorer. Let’s copy and paste this hash into the blockchain explorer available at blockchain.info. We can see that this hash is for block number 0, and that it has only one transaction in it which is the mining reward, and the reward amount of 50 Bitcoin was given to this Bitcoin address. We can also see this 50 Bitcoin reward for the genesis block in the original source code. The genesis block is a special case needed to start the blockchain and is the only block that is hard-coded, whereas every subsequent block is calculated using proof-of-work. Satoshi’s motivation for creating Bitcoin is revealed in the piece of data he included in the genesis block: a newspaper headline from The Times that read ‘Chancellor on brink of second bailout for banks’. The date of the newspaper is proof that the genesis block was created on or after Jan 3 2009. Satoshi developed the source code mostly himself up until mid-2010, when he handed it off to the open-source community. It is now maintained under the project called Bitcoin Core. The software is currently at version 0.15.1 and is available for download at bitcoin.org. This is still the most popular Bitcoin client, and its estimated that there are over 10 thousand nodes running the Bitcoin network today using various clients. Satoshi disappeared from public view in late 2010, his identity still unknown to this day. The only way someone could prove that they are Satoshi is by using the same encryption keys used when posting the original whitepaper in the online cryptography forum. To read more check out https://blockgeeks.com/
Views: 14186 Blockgeeks
Ethereum Name Service Explained
Ethereum Name Service Explained https://blockgeeks.com In this lesson we’re going to learn about ENS, or Ethereum Name Service, and how it helps us provide human-readable names for our dapps ENS is a project within the Ethereum dev community who’s goal is to create a decentralized domain name registry for the decentralized web. Today, we use DNS servers to resolve our .com domain names to IP addresses. But a centralized name registry like DNS is vulnerable to spoofing and denial-of-service attacks. Since ENS is built on top of the Ethereum blockchain, it is decentralized and doesn’t suffer from the same vulnerabilities as DNS. ENS started out on the Ropsten testnet, but launched on the mainnet in May 2017. The initial proposals describing ENS and its registration spec are EIP137 and EIP162, respectively. The Ethereum address of the main ENS contract is visible on their website, and we can even go and take a look at its source code on etherscan (0x6090A6e47849629b7245Dfa1Ca21D94cd15878Ef). One thing to note in the source code is that ENS actually maps hashes of domain names to addresses, not the actual domain name itself. This is to prevent spamming when registering a new domain as the name is never visible in the contract, only its hash. This is also a storage optimization because hashes take up a constant amount of space no matter the length of the domain name. ENS is used to resolve human-readable .eth domain names to Ethereum account addresses, smart contract addresses, IPFS/Swarm content hashes, and even more interesting use cases in the future that we haven’t thought of yet. ENS domain names will be a big step in bringing mass adoption as dealing with long hexadecimal strings can be daunting to the average person, and the strings are just not easy to remember and pass around. Another issue that ENS tries to solve is that of domain squatting: people buying domains because they think it will be valuable in the future and just sitting on it and never actually doing anything with it. This is a popular strategy in the world of DNS to make good money; as long as you bought the domain name first you can sell it to whoever you like for whatever price. ENS tries to counter this with some techniques like using a vickerey auction to give the rights to a domain name. The idea behind the auction process is that the party willing to pay most for the domain will be the one that probably needs it most. This prevents squatters from buying another brand’s domain name early and just sitting on it. With this auction process, the brand would also have a chance to bid on the domain. A big difference here from DNS is that you are not actually “buying” the domain name in ENS; you are simply locking up ether in a smart contract that gives you rights to the domain for a certain amount of time. If you let go of the domain name, your locked up ether is returned to you. This is in contrast with DNS, where you dont get any money back after your domain expires. There are several ways you can register a domain on ENS, even through command line, but we’re going to see the simplest way which is through their website at registrar.ens.domains. You should give their website a read, but one important thing to note is that the current name registrar is temporary. It is expected that 1-2 years from now a permanent registrar will be deployed with more improvements and techniques to prevent squatting. The current temporary registrar is to create community awareness and serve as an initial testing of the concept. Once the permanent registrar is deployed, all domains from the current registrar will be moved over. There are also a certain set of rules to follow for ENS domain names, like being at least 7 characters long. This is also a strategy to prevent squatters from getting the valuable shortname domains early on. As the project evolves and gains awareness in the community, shorter domain names will become available for auction. To read more visit us at blockgeeks.com !
Views: 1536 Blockgeeks
The Cryptoeconomic Properties of Bitcoin
The Cryptoeconomic Properties of Bitcoin - https://blockgeeks.com/ The term “cryptoeconomics” causes a lot of confusion. People are often unclear on what it is supposed to mean. The word itself can be misleading, as it suggests that there is a parallel “crypto” version of the whole of economics. This is wrong. In simple terms, cryptoeconomics is the use of incentives and cryptography to design new kinds of systems, applications, and networks. Cryptoeconomics is specifically about building things. Cryptoeconomics is not a subfield of economics, but rather an area of applied cryptography that takes economic incentives and economic theory into account. Bitcoin, ethereum, zcash and all other public blockchains are products of cryptoeconomics. To understand why the coins on these blockchains have value, we first need to understand what money really is and what makes it valuable. In the most basic sense, money facilitates trade. In earlier societies, money could be a bag of flour, a fur hide, or even a goat. It could be anything, as long as the person receiving it deemed it valuable enough to provide a good or service for it in return. For hundreds of years people traded goods and services directly, and money as we understand it today didn’t exist. Let’s say I have a farm with an excess supply of wheat. I could offer a bag of wheat to the local shoemaker for a pair of shoes. For this transaction to happen, I need to want shoes, and the shoemaker needs to want wheat. But what if the shoemaker doesn’t want wheat? Or I had a bad harvest and don’t have enough wheat to spare? If I don’t have something the shoemaker wants, I can’t use his services. This was a real problem. Different people needed different things at different times, so no one could guarantee that they had the required items to make a successful trade for even the most basic amenities they needed to survive, like food or warm clothing. People needed something that was valuable to everyone all the time. So instead, they started trading coins with each other that acted as placeholders for value. And what made these coins special was that everyone agreed they had the same value. This gave people the guarantee they needed: they could always trade coins for any good or service, which made them want to collect more and more coins, because the more coins you had, the more things you could trade them for. Fast forward a few hundred years, and you can see the basic premise of money hasn’t changed much. We all agree on what a dollar is worth, and each of us has a certain number of dollars, which we use to get goods and services. We also provide goods and services to get more dollars. The only thing that makes our dollars valuable is that we know we can use them to get things. That, and the fact that we can’t just magically produce them whenever we want. So for money to have value, everyone needs to agree to give it value, and it has to be scarce. So how does Bitcoin achieve this? Bitcoin’s promise of a decentralized currency is very valuable. It functions like digital cash - it has all the convenience and speed of digitally transferring money, without having to rely on a third party like a bank. These properties, as well as the security in the network that ensures they can be fulfilled, makes Bitcoin something people want to assign value to. With bitcoin, you can send money across the world in minutes, without having to worry about exchanging currencies or going through intermediary banks. You also know that your bitcoins have value on an international level. So you’re not tied to your bank, or your particular country per se. Some of the biggest markets for bitcoins are in countries like Greece or Venezuela, where their national currency’s value is very unstable. With Bitcoin, people in these countries know that their assets won’t suddenly become worthless when their national economy takes a hit. This is an offer people find very appealing, because it goes a step further to give your assets value on the international market and facilitates direct trade on a global scale. Other tech companies tried to come up with digital cash couldn’t get around the problem of trust. To read more, check out https://blockgeeks.com/
Views: 3666 Blockgeeks
What is an Airdrop and How Do You Get Them?
What is an Airdrop and How Do You Get Them? https://blockgeeks.com/guides/airdrops/ This might sound unbelievable, but Airdrops are basically free cryptocurrency. But is anything ever really free? In this guide, we examine why projects give out Airdrops, how to receive airdrops, what the benefit is to projects, what the benefit is to you, and some scams to watch out for. For more videos, courses, and guides, visit us over at https://blockgeeks.com! What does “Airdrop” mean? In its literal definition and historical use, an airdrop is a tactic by which crates of food and essential supplies are dropped via airplane to people in need. So, when you see old war footages of soldiers dropping crates of food/supplies etc., that is basically an airdrop. The Ultimate Guide to Airdrops (Free Tokens) : What Are Airdrops? The Ultimate Guide to Airdrops (Free Tokens) Image Credit: Millitary.com In the context of cryptocurrencies, however, this takes a whole new meaning. If you are involved in the crypto space, then you must have come across this term before. The purpose of this article is to clear up all the confusion that you may have surrounding this term. Also, hopefully, you will learn how to carefully dissect airdrops to make yourself a pretty nifty profit from them! Airdrops are basically a process by which a company distributes its tokens to the wallets of certain users, completely free of charge. So, the most obvious question that you are thinking about right now is, why will companies simply give their tokens away? What Are Airdrops? And Why Companies Do It What Are Airdrops? The Ultimate Guide to Airdrops (Free Tokens) There are actually several reasons why companies may want to conduct airdrops: Generating Awareness Understanding the users Raising Funds Rewarding or Inspiring Loyalty Wider Distribution of Tokens Hard Forks
Views: 3563 Blockgeeks
Understanding Vyper: The slick New Ethereum language
Understanding Vyper: The slick New Ethereum language https://blockgeeks.com/guides/understanding-vyper/ Vyper is a language similar to Python, but for coding smart contracts. We wanted to give you the low-down on the philosophy behind Vyper, and what it offers developers that use it. Learning the language in 60 seconds would be impossible, but let’s join Bardia for a breakdown of the key points that you need to know before diving head first into Vyper code. If you want to learn more about Vyper, Solidity, or any other smart contract development tools, visit us over at www.blockgeeks.com ==== Vyper is a general-purpose, experimental programming language that compiles down to EVM (Ethereum Virtual Machine) bytecode, as does Solidity. However, Vyper is designed to massively simplify the process in order to create easier-to-understand Smart Contracts that are more transparent for all parties involved, and have fewer points of entry for an attack. Any code targeting the EVM must be hyper-efficient to minimize the gas needed for Smart Contracts to execute, as a contract with inefficient code literally costs more ether to execute, and can quickly become prohibitively expensive, especially in use-cases such as micro-transactions. The end result is that Vyper looks logically similar to Solidity, and syntactically similar to Python, but without many of the Object Oriented Programming paradigms – perhaps requiring a new paradigm definition for transactional programming. Learning these logical and syntactical differences now will help you become a world-class Vyper developer since Vyper is still in v0.1.0-beta.1 as of June 2018!
Views: 3550 Blockgeeks
Building an Open Auction Contract in Vyper!
Building an Open Auction Contract in Vyper! https://blockgeeks.com/ Join Bardia as he goes through the basics of the all-new exciting Ethereum programming language, Vyper, based on Python! Watch Bardia use the new experimental language to code up an open auction contract! To learn more about coding smart contracts, visit us at httpswww.blockgeeks.com To learn about auditing smart contracts and making them secure, visit http://bountyone.io/ == Vyper is a general-purpose, experimental programming language that compiles down to EVM (Ethereum Virtual Machine) bytecode, as does Solidity. However, Vyper is designed to massively simplify the process in order to create easier-to-understand Smart Contracts that are more transparent for all parties involved, and have fewer points of entry for an attack. Key Improvement 1: Simplicity Vyper does not contain many of the constructs familiar to most programmers: Class inheritance, function overloading, operator overloading, and recursion. None of these are technically necessary for a Turing-complete language, and they represent security risks by increasing complexity. Due to this complexity, these constructs would make Smart Contracts too difficult to understand and audit by a lay-person, seen in Solidity contracts.
Views: 3705 Blockgeeks
What is Aion Blockchain? Easy To Understand Video
What is Aion Blockchain? Easy To Understand Video https://blockgeeks.com/guides/aion-blockchain/ With so many different crypto platforms to choose from, how can anyone decide which one is the one they want to use the most? Is it even possible to connect different public blockchains? Check out this video with our instructor Haseeb to learn about Aion, a multi-tier system designed to address unsolved questions of scalability, and interoperability. Check out the full course on our website: www.blockgeeks.com Interested in winning some ETH in a mini hackathon? Check out bountyone.io === Aion Blockchain is the first multi-tier blockchain network designed to interconnect these various blockchain entities. In this guide, we are going to to do an in-depth study of Aion. With their main net releasing in the upcoming month, now is as a good a time as any to get acquainted with this, potentially groundbreaking, company.
Views: 991 Blockgeeks
Exploring Hyperledger Composer
Exploring Hyperledger Composer https://blockgeeks.com/guides/hyperledger/ Join Niloo as she walks through using Hyperledger Fabric with the Composer IDE. Learn how to instantiate and test a private network and build a simple commodity trading app. For more blockchain guides, courses, and videos, visit us over at blockgeeks.com! Check out our sister site bountyone.io if you need a your code audited for security! === Hyperledger Composer is an extensive, open development toolset and framework to make developing blockchain applications easier. Our primary goal is to accelerate time to value, and make it easier to integrate your blockchain applications with the existing business systems. You can use Composer to rapidly develop use cases and deploy a blockchain solution in weeks rather than months. Composer allows you to model your business network and integrate existing systems and data with your blockchain applications. Hyperledger Composer supports the existing Hyperledger Fabric blockchain infrastructure and runtime, which supports pluggable blockchain consensus protocols to ensure that transactions are validated according to policy by the designated business network participants. Everyday applications can consume the data from business networks, providing end users with simple and controlled access points. You can use Hyperledger Composer to quickly model your current business network, containing your existing assets and the transactions related to them; assets are tangible or intangible goods, services, or property. As part of your business network model, you define the transactions which can interact with assets. Business networks also include the participants who interact with them, each of which can be associated with a unique identity, across multiple business networks.
Views: 6425 Blockgeeks
Vitalik Buterin Talks Blockchain Education
Vitalik Buterin, creator of Ethereum, stopped by our office last week for a surprise visit. Jack was able to record a quick interview with him about blockchain education, as well as his future plans and projects. For more blockchain tutorials, guides, and content, be sure to visit us at blockgeeks.com
Views: 3551 Blockgeeks
What is Decred?
What is Decred? https://blockgeeks.com/guides/decred/ Decentralized Credits, or Decred, is a cryptocurrency with a unique take on consensus and governance. In this guide, we explore what makes the Decred network nearly 22x more expensive to attack than Bitcoin, as well as their clearly defined and tested governance system. For more videos, courses, and guides, visit us over at https://blockgeeks.com!
Views: 492 Blockgeeks