Understanding how blockchain works and identifying myths about its powers are the first steps to developing blockchain technologies
Video: Blockchain in 60 seconds
After spending two years researching blockchain and the evolution of advanced ledger technologies, I still find a great spectrum of understanding across my clients and business at large about blockchain. While ledger superpowers like Hyperledger, IBM, Microsoft and R3 are emerging, there remains a long tail of startups trying to innovate on the first generation public blockchains. Most of the best-selling blockchain books confine themselves to Bitcoin, and extrapolate its apparent magic into a dizzying array of imagined use cases. And I'm continuously surprised to find people who are only just hearing about blockchain now.
It can seem that everyone is talking about blockchain and ledger technologies, but the truth is most people are not yet up to speed. No one should be shy to ask what blockchain is really all about.
Many blockchain primers and infographics dive into the cryptography, trying to explain to lay people how "consensus algorithms", "hash functions" and digital signatures all work. In their enthusiasm, they can speed past the fundamental question of what blockchain was really designed to do. I've long been worried about a lack of critical thinking around blockchain and the activity it's inspired. If you want to develop blockchain applications you only need to know what blockchain does, and not how it does it.
So I've written a report that explains how the blockchain works. It examines the founding principles of blockchain, describes its properties, and dispels common myths about its powers. The explanation below is an abridged excerpt from the report.
WHAT IS BLOCKCHAIN?
Blockchain is an algorithm and distributed data structure for managing electronic cash without a central administrator among people who know nothing about one another. Originally designed for the crypto-currency Bitcoin, the blockchain architecture was driven by a radical rejection of at (government-guaranteed) money and bank-controlled payments.
Blockchain is a special instance of Distributed Ledger Technologies (DLTs), almost all of which have emerged in Bitcoin's wake.
HOW DOES BLOCKCHAIN WORK?
Blockchain is a Distributed Ledger Technology (DLT) that was invented to support the Bitcoin cryptocurrency. Bitcoin was motivated by an extreme rejection of government-guaranteed money and bank-controlled payments. The developer of Bitcoin, Satoshi Nakamoto envisioned people spending money without friction, intermediaries, regulation or the need to know or trust other parties.
Technically, the original blockchain is separable from Bitcoin, but this report will show that the blockchain design is so specific to Bitcoin that it's not a good fit for much else.
The central problem in electronic cash is Double Spend. Because pure electronic money is just data, nothing stops a currency holder from trying to spend it twice. Blockchain solves the Double Spend problem without a digital reserve fund or similar form of umpire.
Blockchain monitors and verifies Bitcoin transactions by calling upon a decentralized network of volunteer-run nodes to, in effect, vote on the order in which transactions occur. The network's algorithm ensures that each transaction is unique.
Several thousand nodes make up the Bitcoin network. Once a majority of nodes reaches consensus that all transactions in the recent past are unique (that is, not double spent), they are cryptographically sealed into a block. Each new block is linked to previously sealed blocks to create a chain of accepted history, thereby preserving a verified record of every spend.
The Bitcoin blockchain's functionality and security results from the network of thousands of nodes agreeing on the order of transactions. The diffuse nature of the network ensures transactions and balances are recorded without bias and are resistant to attack by even a relatively large number of bad actors. In fact, the record of transactions and balances remains secure as long as a simple majority (51 percent) of nodes remains independent. Thus, the integrity of the blockchain requires a great many participants.
One of the Bitcoin blockchain's most innovative aspects is how it incentivizes nodes to participate in the intensive consensus-building process by randomly rewarding one node with a fixed bounty (currently 12.5 BTC) every time a new block is settled and committed to the chain. This accumulation of Bitcoin in exchange for participation is called "mining" and is how new currency is added to the total system afloat.
Cryptocurrency Wallet Guide: A Step-By-Step Tutorial
Use this straightforward guide to learn what a cryptocurrency wallet is, how they work and discover which ones are the best on the market.
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.
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.
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.
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. Blockchain.info
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. Mycelium
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. Ledger Nano S
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. Bitaddress.org
Are Cryptocurrency wallets secure?
Wallets are secure to varying degrees. The level of security depends on the type of wallet you use (desktop, mobile, online, paper, hardware) and the service provider. A web server is an intrinsically riskier environment to keep your currency compared to offline. Online wallets can expose users to possible vulnerabilities in the wallet platform which can be exploited by hackers to steal your funds. Offline wallets, on the other hand, cannot be hacked because they simply aren’t connected to an online network and don’t rely on a third party for security.
Although online wallets have proven the most vulnerable and prone to hacking attacks, diligent security precautions need to be implemented and followed when using any wallet. Remember that no matter which wallet you use, losing your private keys will lead you to lose your money. Similarly, if your wallet gets hacked, or you send money to a scammer, there is no way to reclaim lost currency or reverse the transaction. You must take precautions and be very careful!
Backup your wallet. Store only small amounts of currency for everyday use online, on your computer or mobile, keeping the vast majority of your funds in a high security environment. Cold or offline storage options for backup like Ledger Nano or paper or USB will protect you against computer failures and allow you to recover your wallet should it be lost or stolen. It will not, however, protect you against eager hackers. The reality is, if you choose to use an online wallet there are inherent risks that can’t always be protected against.
Update software. Keep your software up to date so that you have the latest security enhancements available. You should regularly update not only your wallet software but also the software on your computer or mobile.
Add extra security layers. The more layers of security, the better. Setting long and complex passwords and ensuring any withdrawal of funds requires a password is a start. Use wallets that have a good reputation and provide extra security layers like two-factor authentication and additional pin code requirements every time a wallet application gets opened. You may also want to consider a wallet that offers multisig transactions like Armory or Copay. A multisig or multi-signature wallet requires the permission of another user or users before a transaction can be made.
Multi-currency or single use?
Although Bitcoin is by far the most well-known and popular digital currency, hundreds of new cryptocurrencies(referred to as altcoins) have emerged, each with distinctive ecosystems and infrastructure. If you’re interested in using a variety of cryptocurrencies, the good news is, you don’t need set up a separate wallet for each currency. Instead of using a cryptocurrency wallet that supports a single currency, it may be more convenient to set up a multi-currency wallet which enables you to use several currencies from the same wallet.
Are there any transaction fees?
There is no straightforward answer here.
In general, transaction fees are a tiny fraction of traditional bank fees. Sometimes fees need to be paid for certain types of transactions to network miners as a processing fee, while some transactions don’t have any fee at all. It’s also possible to set your own fee. As a guide, the median transaction size of 226 bytes would result in a fee of 18,080 satoshis or $0.12. In some cases, if you choose to set a low fee, your transaction may get low priority, and you might have to wait hours or even days for the transaction to get confirmed. If you need your transaction completed and confirmed promptly, then you might need to increase the amount you’re willing to pay. Whatever wallet you end up using, transaction fees are not something you should worry about. You will either pay minuscule transaction fees, choose your own fees or pay no fees at all. A definite improvement from the past!
Are cryptocurrency wallets anonymous?
Kind of, but not really. Wallets are pseudonymous. While wallets aren’t tied to the actual identity of a user, all transactions are stored publicly and permanently on the blockchain. Your name or personal street address won’t be there, but data like your wallet address could be traced to your identity in a number of ways. While there are efforts underway to make anonymity and privacy easier to achieve, there are obvious downsides to full anonymity. Check out the DarkWallet project that is looking to beef up privacy and anonymity through stealth addresses and coin mixing.
Which Cryptocurrency wallet is the best?
There is an ever-growing list of options. Before picking a wallet, you should, however, consider how you intend to use it.
Do you need a wallet for everyday purchases or just buying and holding digital currency for an investment?
Do you plan to use several currencies or one single currency?
Do you require access to your digital wallet from anywhere or only from home?
Take some time to assess your requirements and then choose the most suitable wallet for you.
Paper Wallet
Bread Wallet
Bread Wallet is a simple mobile Bitcoin digital wallet that makes sending bitcoins as easy as sending an email. The wallet can be downloaded from the App Store or Google Play. Bread Wallet offers a standalone client, so there is no server to use when sending or receiving bitcoins. That means users can access their money and are in full control of their funds at all times. Overall, Bread Wallet’s clean interface, lightweight design and commitment to continually improve security, make the application safe, fast and a pleasure to use for both beginners and experienced users alike.
Pros: Good privacy & security, beginner friendly, simple & clean, open source software, free.
Cons: No web or desktop interface, lacks features, hot wallet.
Mycelium
Advanced users searching for a Bitcoin mobile digital wallet, should look no further than mycelium. The Mycelium mobile wallet allows iPhone and Android users to send and receive bitcoins and keep complete control over bitcoins. No third party can freeze or lose your funds! With enterprise-level security superior to most other apps and features like cold storage and encrypted PDF backups, an integrated QR-code scanner, a local trading marketplace and secure chat amongst others, you can understand why Mycelium has long been regarded as one of the best wallets on the market.
Pros: Good privacy, advanced security, feature-rich, open source software, free
Cons: No web or desktop interface, hot wallet, not for beginners
Exodus
Exodus is a relatively new and unknown digital wallet that is currently only available on the desktop. It enables the storage and trading of Bitcoin, Ether, Litecoins, Dogecoins and Dash through an incredibly easy to use, intuitive and beautiful interface. Exodus also offers a very simple guide to backup your wallet. One of the great things about Exodus is that it has a built-in shapeshift exchange that allows users to trade altcoins for bitcoins and vice versa without leaving the wallet.
Pros: Good privacy & security, beginner friendly, intuitive, easy to use, in-wallet trading, supports multiple currencies, open source software, free.
Cons: Hot wallet, no web interface or mobile app
Copay
Created by Bitpay, Copay is one of the best digital wallets on the market. If you’re looking for convenience, Copay is easily accessed through a user-friendly interface on desktop, mobile or online. One of the best things about Copay is that it’s a multi-signature wallet so friends or business partners can share funds. Overall, Copay has something for everyone. It’s simple enough for entry-level users but has plenty of additional geeky features that will impress more experienced players as well.
Pros: Good privacy & security, multisig transactions, multiple platforms & devices, multiple wallet storage, beginner friendly, open source software, free
Cons: Can be slow & unresponsive, limited user support
Jaxx
Jaxx is a multi-currency Ether, Ether Classic, Dash, DAO, Litecoin, REP, Zcash, Rootstock, Bitcoin wallet and user interface. Jaxx has been designed to deliver a smooth Bitcoin and Ethereum experience. It is available on a variety of platforms and devices (Windows, Linux, Chrome, Firefox, OSX, Android mobile & tablet, iOS mobile & tablet) and connects with websites through Firefox and Chrome extensions. Jaxx allows in wallet conversion between Bitcoin, Ether and DAO tokens via Shapeshift and the import of Ethereum paper wallets. With an array of features and the continual integration of new currencies, Jaxx is an excellent choice for those who require a multi-currency wallet.
Pros: Good privacy & security, Multi-currency, wallet linking across multiple platforms, great user support, feature rich, user-friendly, free.
Cons: Code is not open source, can be slow to load.
Armory
Armory is an open source Bitcoin desktop wallet perfect for experienced users that place emphasis on security. Some of Armory’s features include cold storage, multi-signature transactions, one-time printable backups, multiple wallets interface, GPU-resistant wallet encryption, key importing, key sweeping and more. Although Armory takes a little while to understand and use to it’s full potential, it’s a great option for more tech-savvy bitcoiners looking to keep their funds safe and secure.
Pros: Good privacy, great security features, multi-signature options, solid cold storage options, free.
Cons: Only accessible via the desktop client, not for beginners.
Trezor
Trezor is a hardware Bitcoin wallet that is ideal for storing large amounts of bitcoins. Trezor cannot be infected by malware and never exposes your private keys which make it as safe as holding traditional paper money. Trezor is open source and transparent, with all technical decisions benefiting from wider community consultation. It’s easy to use, has an intuitive interface and is Windows, OS X and Linux friendly. One of the few downsides of the Trezor wallet is that it must be with you to send bitcoins. This, therefore, makes Trezor best for inactive savers, investors or people who want to keep large amounts of Bitcoin highly secure.
Pros: Good security & privacy, cold storage, easy to use a web interface, in-built screen, open source software, beginner friendly.
Cons: Costs $99, must have device to send bitcoins
Ledger Nano
The Ledger Wallet Nano is a new hierarchical deterministic multisig hardware wallet for bitcoin users that aims to eliminate a number of attack vectors through the use of a second security layer. This tech-heavy description does not mean much to the average consumer, though, which is why I am going to explain it in plain language, describing what makes the Ledger Wallet Nano tick. In terms of hardware, the Ledger Wallet Nano is a compact USB device based on a smart card. It is roughly the size of a small flash drive, measuring 39 x 13 x 4mm (1.53 x 0.51 x 0.16in) and weighing in at just 5.9g.
Pros:
Screen/device protected by metal swivel cover
Multi-Currency support
3rd-Party apps can run from device
U2F support
When recovering wallet from seed, the whole process can be done from the device without even connecting it to a computer!
Fairly inexpensive (~$65 USD)
Cons:
Not as advanced wallet software (no transaction labeling)
No ability to create hidden accounts
No password manager
Green Address
Green Address is a user-friendly Bitcoin wallet that’s an excellent choice for beginners. Green Address is accessible via desktop, online or mobile with apps available for Chrome, iOS, and Android. Features include multi-signature addresses & two-factor authentications for enhanced security, paper wallet backup, and instant transaction confirmation. A downside is that Green Address is required to approve all payments, so you do not have full control over your spending.
Cons: Hot wallet, average privacy, the third party must approve payments.
Blockchain (dot) info
Blockchain is one of the most popular Bitcoin wallets. Accessing this wallet can be done from any browser or smartphone. Blockchain.info provides two different additional layers. For the browser version, users can enable two-factor authentication, while mobile users can activate a pin code requirement every time the wallet application is opened. Although your wallet will be stored online and all transactions will need to go through the company’s servers, Blockchain.info does not have access to your private keys. Overall, this is a well-established company that is trusted throughout the Bitcoin community and makes for a solid wallet to keep your currency.
Pros: Good security, easy to use web & mobile interface, well-known & trusted company, beginner friendly, free.
Cons: Hot wallet, weak privacy, third party trust required, has experienced outages.
Bitcoin Alt Coin Exchanges
Bitcoin exchanges are digital marketplaces where traders can buy and sell bitcoins and alt coins using different fiat currencies or altcoins. Exchanges also act as wallets.
Blockchain explained in plain English
Cryptocurrency Wallet Guide: A Step-By-Step Tutorial
