Bitcoin (₿) is a decentralized digital currency that can be transferred on the peer-to-peer bitcoin network. Bitcoin transactions are verified by network nodes through cryptography and recorded in a public distributed ledger called a blockchain. The cryptocurrency was invented in 2008 by an unknown person or group of people using the name Satoshi Nakamoto. The currency began use in 2009, when its implementation was released as open-source software.: ch. 1
Bitcoin has been described as an economic bubble by at least eight Nobel Memorial Prize in Economic Sciences recipients.
The word bitcoin was defined in a white paper published on 31 October 2008. It is a compound of the words bit and coin. No uniform convention for bitcoin capitalization exists; some sources use Bitcoin, capitalized, to refer to the technology and network and bitcoin, lowercase, for the unit of account. The Wall Street Journal, The Chronicle of Higher Education, and the Oxford English Dictionary advocate the use of lowercase bitcoin in all cases.
A few local and national governments are officially using bitcoin in some capacity; El Salvador and the Central African Republic have adopted Bitcoin as legal tender, while Ukraine is accepting bitcoin donations to fund the resistance against the Russian invasion.
What Is Bitcoin?
Bitcoin is a cryptocurrency, a virtual currency designed to act as money and a form of payment outside the control of any one person, group, or entity, thus removing the need for third-party involvement in financial transactions. It is rewarded to blockchain miners for the work done to verify transactions and can be purchased on several exchanges.
Bitcoin was introduced to the public in 2009 by an anonymous developer or group of developers using the name Satoshi Nakamoto.
It has since become the most well-known cryptocurrency in the world. Its popularity has inspired the development of many other cryptocurrencies. These competitors either attempt to replace it as a payment system or are used as utility or security tokens in other blockchains and emerging financial technologies.
Learn more about the cryptocurrency that started it all—the history behind it, how it works, how to get it, and what it can be used for.
Can bitcoin be converted to cash?
Bitcoin can be exchanged for cash just like any asset. There are numerous cryptocurrency exchanges online where people can do this but transactions can also be carried out in person or over any communications platform, allowing even small businesses to accept bitcoin. There is no official mechanism built into bitcoin to convert to another currency.
Nothing inherently valuable underpins the bitcoin network. But this is true for many of the world’s most stable national currencies since leaving the gold standard, such as the US dollar and UK pound.
What is the purpose of bitcoin?
Bitcoin was created as a way for people to send money over the internet. The digital currency was intended to provide an alternative payment system that would operate free of central control but otherwise be used just like traditional currencies.
Who invented bitcoin?
In 2008 the domain name .org was bought and an academic white paper titled Bitcoin: A Peer-to-Peer Electronic Cash System was uploaded. It set out the theory and design of a system for a digital currency free of control from any organization or government.
The author, going by the name Satoshi Nakamoto, wrote: “The root problem with conventional currencies is all the trust that’s required to make it work. The central bank must be trusted not to debase the currency, but the history of fiat currencies is full of breaches of that trust.”
The following year the software described in the paper was finished and released publicly, launching the bitcoin network on 9 January 2009.
Nakamoto continued working on the project with various developers until 2010 when he or withdrew from the project and left it to its own devices. The real identity of Nakamoto has never been revealed and they have not made any public statement in years.
Now the software is open source, meaning that anyone can view, use or contribute to the code for free. Many companies and organizations work to improve the software, including MIT.
What are the problems with bitcoin?
There have been several criticisms of bitcoin, including that the mining system is enormously energy hungry. The University of Cambridge has an online calculator that tracks energy consumption and at the beginning of 2021, it was estimated to use over 100 terawatt hours annually. For perspective, in 2016 the United Kingdom used 304 terawatt hours in total.
Cryptocurrency has also been linked to criminality, with critics pointing out to it is a perfect way to make black market transactions. In reality, cash has provided this function for centuries, and the public ledger of bitcoin may actually be a tool for law enforcement.
Launched in 2009, Bitcoin is the world’s largest cryptocurrency by market capitalization.
Unlike fiat currency, Bitcoin is created, distributed, traded, and stored using a decentralized ledger system known as a blockchain.
Bitcoin’s history as a store of value has been turbulent; it has gone through several boom and bust cycles over its relatively short lifespan.
As the earliest virtual currency to meet widespread popularity and success, Bitcoin has inspired a host of other cryptocurrencies in its wake.
Bitcoin (BTC) Definition
Investopedia / Julie Bang
In August 2008, the domain name Bitcoin.org was registered.
Today, at least, this domain is WhoisGuard Protected, meaning the identity of the person who registered it is not public information.
In October 2008, a person or group using the name Satoshi Nakamoto announced the Cryptography Mailing List at metzdowd.com: “I’ve been working on a new electronic cash system that’s fully peer-to-peer, with no trusted third party.” This now-famous white paper published on Bitcoin.org, entitled “Bitcoin: A Peer-to-Peer Electronic Cash System,” would become the Magna Carta for how Bitcoin operates today.
On Jan. 3, 2009, the first Bitcoin block was mined—Block 0. This is also known as the “genesis block” and contains the text: “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks,” perhaps proof that the block was mined on or after that date, and maybe also as relevant political commentary.
On Jan. 8, 2009, the first version of the Bitcoin software was announced to the Cryptography Mailing List, and on Jan. 9, 2009, Block 1 was mined, and Bitcoin mining commenced in earnest.
Bitcoin rewards are halved every 210,000 blocks. For example, the block reward was 50 new bitcoins in 2009. On May 11, 2020, the third halving occurred, bringing the reward for each block discovery down to 6.25 bitcoins.
One bitcoin is divisible to eight decimal places (100 millionths of one bitcoin), and this smallest unit is referred to as a satoshi.
If necessary, and if the participating miners accept the change, Bitcoin could eventually be made divisible to even more decimal places.
Bitcoin, as a form of currency, isn’t too complicated to understand. For example, if you own a bitcoin, you can use your cryptocurrency wallet to send smaller portions of that bitcoin as payment for goods or services. However, it becomes very complex when you try to understand how it works.
Bitcoin’s Blockchain Technology
Cryptocurrencies are part of a blockchain and the network required to power it. A blockchain is a distributed ledger, a shared database that stores data. Data within the blockchain are secured by encryption methods. When a transaction takes place on the blockchain, information from the previous block is copied to a new block with the new data, encrypted, and the transaction is verified by validators—called miners—in the network. When a transaction is verified, a new block is opened, and a Bitcoin is created and given as a reward to the miner(s) who verified the data within the block—they are then free to use it, hold it, or sell it.
Bitcoin uses the SHA-256 hashing algorithm to encrypt the data stored in the blocks on the blockchain. Simply put, transaction data stored in a block is encrypted into a 256-bit hexadecimal number. That number contains all of the transaction data and information linked to the blocks before that block.
Data linked between blocks is what led to the ledger being called a blockchain.
Transactions are placed into a queue to be validated by miners within the network. Miners in the Bitcoin blockchain network all attempt to verify the same transaction simultaneously. The mining software and hardware work to solve the nonce, a four-byte number included in the block header that miners are attempting to solve. The block header is hashed, or randomly regenerated by a miner repeatedly until it meets a target number specified by the blockchain. The block header is “solved,” and a new block is created for more transactions to be encrypted and verified.
What is bitcoin mining?
Mining is the process that maintains the bitcoin network and also how new coins are brought into existence.
All transactions are publicly broadcast on the network and miners bundle large collections of transactions together into blocks by completing a cryptographic calculation that’s extremely hard to generate but very easy to verify. The first miner to solve the next block broadcasts it to the network and if proven correct is added to the blockchain. That miner is then rewarded with an amount of newly created bitcoin.
Inherent in the bitcoin software is a hard limit of 21 million coins. There will never be more than that in existence. The total number of coins will be in circulation by 2140. Roughly every four years the software makes it twice as hard to mine bitcoin by reducing the size of the rewards.
When bitcoin was first launched it was possible to almost instantaneously mine a coin using even a basic computer. Now it requires rooms full of powerful equipment, often high-end graphics cards that are adept at crunching through the calculations, which when combined with a volatile bitcoin price can sometimes make mining more expensive than it is worth.
Miners also choose which transactions to bundle into a block, so fees of a varying amounts are added by the sender as an incentive. Once all coins have been mined, these fees will continue as an incentive for mining to continue. This is needed as it provides the infrastructure of the Bitcoin network.
How to Mine Bitcoin
A variety of hardware and software can be used to mine Bitcoin. When Bitcoin was first released, it was possible to mine it competitively on a personal computer. However, as it became more popular, more miners joined the network, which lowered the chances of being the one to solve the hash. You can still use your personal computer as a miner if it has newer hardware, but the chances of solving a hash are individually are minuscule.
This is because you’re competing with a network of miners that generate around 220 quintillion hashes (220 exa hashes) per second.
Machines, called Application Specific Integrated Circuits (ASICs), have been built specifically for mining—can generate around 255 trillion hashes per second. In contrast, a computer with the latest hardware hashes around 100 mega hashes per second (100 million).
To successfully become a Bitcoin miner, you have several options. You can use your existing personal computer to use mining software compatible with Bitcoin and join a mining pool. Mining pools are groups of miners that combine their computational power to compete with the large ASIC mining farms.
You increase your chances of being rewarded by joining a pool, but rewards are significantly decreased because they are shared.
If you have the financial means, you could also purchase an ASIC miner. You can generally find a new one for around $20,000, but used ones are also sold by miners as they upgrade their systems. There are some significant costs such as electricity and cooling to consider if you purchase one or more ASICs.
There are several mining programs to choose from and many pools you can join. Two of the most well-known programs are CGMiner and BFGMiner. When choosing a pool, it’s important to make sure you find out how they pay out rewards, what any fees might be, and read some mining pool reviews.
Are bitcoins safe?
The cryptography behind bitcoin is based on the SHA-256 algorithm designed by the US National Security Agency. Cracking this is, for all intents and purposes, impossible as there are more possible private keys that would have to be tested (2256) than there are atoms in the universe (estimated to be somewhere between 1078 to 1082).
There have been several high-profile cases of bitcoin exchanges being hacked and funds being stolen, but these services invariably stored the digital currency on behalf of customers. What was hacked in these cases was the website and not the bitcoin network.
In theory, if an attacker could control more than half of all the bitcoin nodes in existence then they could create a consensus that they owned all bitcoin, and embed that into the blockchain. But as the number of nodes grows this becomes less practical.
A real problem is that bitcoin operates without any central authority. Because of this, anyone making an error with a transaction on their wallet has no recourse. If you accidentally send bitcoins to the wrong person or lose your password there is nobody to turn to.
Of course, the eventual arrival of practical quantum computing could break it all. Much cryptography relies on mathematical calculations that are extremely hard for current computers to do, but quantum computers work very differently and may be able to execute them in a fraction of a second.
What is a bitcoin wallet?
A bitcoin wallet is a software program that runs on a computer or a dedicated device that provides the functionality required to secure, send and receive bitcoin. Counterintuitively, the bitcoin itself is not stored in a wallet. Instead, the wallet secures the cryptographic keys — essentially a very specialized type of password — that proves the ownership of a specific amount of bitcoin on the Bitcoin network.
Anytime a bitcoin transaction is executed, ownership of the bitcoin transfers from the sender to the recipient, with the network designating the recipient’s keys as the new “password” for accessing the bitcoin.
Bitcoin uses a system called public-key cryptography (PKC) to preserve the integrity of its blockchain. Originally used to encrypt and decrypt messages, PKC is now commonly used on blockchains to secure transactions. This system allows only individuals with the right set of keys to access specific coins.
There are two types of keys required to own and execute bitcoin transactions: A private key and a public key. Both keys are strings of randomly generated alphanumeric characters used to encrypt and decrypt transactions. On the bitcoin network, PKC implements one-way mathematical functions that are easy to solve in one way and almost impossible to reverse.
The blockchain uses a one-way mathematical algorithm to create a public key from a private key. With this, it is practically impossible to regenerate the private key from the public key, meaning you’d better not lose your keys (or forget your password to access them). Also, you will receive a public address, which is simply the hashed or shorter form of your public key.
This address functions similarly to a house address and is shared to receive bitcoin. On the other hand, the private key must be kept hidden from prying eyes, just as your debit card’s PIN is meant for your eyes alone.
To execute transactions, you are required to use your private key and public key to encrypt and sign your Bitcoin transactions. Also, you have to include the public address of the recipient. With this, only the recipient with the right private key can unlock or claim the transferred bitcoin.
How Do You Buy Bitcoin?
If you don’t want to mine bitcoin, it can be bought using a cryptocurrency exchange. Most people will not be able to purchase an entire BTC because of its price, but you can buy portions of BTC on these exchanges in fiat currency like U.S. dollars. For example, you can buy bitcoin on Coinbase by creating an account and funding it. You can fund your account using your bank account, credit card, or debit card. The following video explains more about buying bitcoin.