The receiver of the first bitcoin transaction was cypherpunk Hal Finney, who had created the first reusable proof-of-work system (RPoW) in 2004.[28] Finney downloaded the bitcoin software on its release date, and on 12 January 2009 received ten bitcoins from Nakamoto.[29][30] Other early cypherpunk supporters were creators of bitcoin predecessors: Wei Dai, creator of b-money, and Nick Szabo, creator of bit gold.[25] In 2010, the first known commercial transaction using bitcoin occurred when programmer Laszlo Hanyecz bought two Papa John's pizzas for ₿10,000.[31]
Conclusion for today’s Ethereum Analysis: Price breaking below ~177.65 implies continuation of the current downtrend in Ethereum. Ethereum analysis for today is carried out on an intraday (4 hour) timeframe candlestick chart that focuses on price action since the last week of June of current date. A head and shoulders top pattern (ideally bearish) that confirmed...
Last week was relatively quiet in Ethereum land; the World Bank sold $33.8 million in another round of its private Ethereum blockchain bonds (not public chain activity but interesting nonetheless) and Mark Carney (Bank of England Governor) discussed the major advantages of a world reserve currency at an annual gathering of central bankers in Wyoming – drawing many parallels to that proposed by Facebook’s Libra cryptocurrency.

NEM — Unlike most other cryptocurrencies that utilize a Proof of Work algorithm, it uses Proof of Importance, which requires users to already possess certain amounts of coins in order to be able to get new ones. It encourages users to spend their funds and tracks the transactions to determine how important a particular user is to the overall NEM network.


In October 2015,[62] a development governance was proposed as Ethereum Improvement Proposal, aka EIP, standardized on EIP-1.[63] The core development group and community were to gain consensus by a process regulated EIP. A few notable decisions were made in the process of EIP, such as EIP-160 (EXP cost increase caused by Spurious Dragon Hardfork)[64] and EIP-20 (ERC-20 Token Standard).[65] In January 2018, the EIP process was finalized and published as EIP-1 status turned "active".[62] Alongside ERC-20, notable EIPs to have become finalised token standards include ERC-721[66] (enabling the creation of non-fungible tokens, as used in Cryptokitties) and as of June 2019, ERC-1155 [67] (enabling the creation of both fungible and non-fungible tokens within a single smart contract with reduced gas costs).

Every 2,016 blocks (approximately 14 days at roughly 10 min per block), the difficulty target is adjusted based on the network's recent performance, with the aim of keeping the average time between new blocks at ten minutes. In this way the system automatically adapts to the total amount of mining power on the network.[7]:ch. 8 Between 1 March 2014 and 1 March 2015, the average number of nonces miners had to try before creating a new block increased from 16.4 quintillion to 200.5 quintillion.[91]

The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media.[226] In the United States, the FBI prepared an intelligence assessment,[227] the SEC issued a pointed warning about investment schemes using virtual currencies,[226] and the U.S. Senate held a hearing on virtual currencies in November 2013.[228] The U.S. government claimed that bitcoin was used to facilitate payments related to Russian interference in the 2016 United States elections.[229]
Miners are the single most important part of any cryptocurrency network, and much like trading, mining is an investment. Essentially, miners are providing a bookkeeping service for their respective communities. They contribute their computing power to solving complicated cryptographic puzzles, which is necessary to confirm a transaction and record it in a distributed public ledger called the Blockchain.

In 2016 a decentralized autonomous organization called The DAO, a set of smart contracts developed on the platform, raised a record US$150 million in a crowdsale to fund the project.[25] The DAO was exploited in June when US$50 million in ether were taken by an unknown hacker.[26][27] The event sparked a debate in the crypto-community about whether Ethereum should perform a contentious "hard fork" to reappropriate the affected funds.[28] As a result of the dispute, the network split in two. Ethereum (the subject of this article) continued on the forked blockchain, while Ethereum Classic continued on the original blockchain.[29] The hard fork created a rivalry between the two networks.
In cryptocurrency networks, mining is a validation of transactions. For this effort, successful miners obtain new cryptocurrency as a reward. The reward decreases transaction fees by creating a complementary incentive to contribute to the processing power of the network. The rate of generating hashes, which validate any transaction, has been increased by the use of specialized machines such as FPGAs and ASICs running complex hashing algorithms like SHA-256 and Scrypt.[30] This arms race for cheaper-yet-efficient machines has been on since the day the first cryptocurrency, bitcoin, was introduced in 2009.[30] With more people venturing into the world of virtual currency, generating hashes for this validation has become far more complex over the years, with miners having to invest large sums of money on employing multiple high performance ASICs. Thus the value of the currency obtained for finding a hash often does not justify the amount of money spent on setting up the machines, the cooling facilities to overcome the enormous amount of heat they produce, and the electricity required to run them.[30][31]
If you happen to own a business and if you’re looking for potential new customers, accepting cryptocurrencies as a form of payment may be a solution for you. The interest in cryptocurrencies has never been higher and it’s only going to increase. Along with the growing interest, also grows the number of crypto-ATMs located around the world. Coin ATM Radar currently lists almost 1,800 ATMs in 58 countries.
^ Iansiti, Marco; Lakhani, Karim R. (January 2017). "The Truth About Blockchain". Harvard Business Review. Harvard University. Retrieved 17 January 2017. The technology at the heart of bitcoin and other virtual currencies, blockchain is an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way.
Mostly due to its revolutionary properties cryptocurrencies have become a success their inventor, Satoshi Nakamoto, didn‘t dare to dream of it. While every other attempt to create a digital cash system didn‘t attract a critical mass of users, Bitcoin had something that provoked enthusiasm and fascination. Sometimes it feels more like religion than technology.
Full clients verify transactions directly by downloading a full copy of the blockchain (over 150 GB As of January 2018).[100] They are the most secure and reliable way of using the network, as trust in external parties is not required. Full clients check the validity of mined blocks, preventing them from transacting on a chain that breaks or alters network rules.[7]:ch. 1 Because of its size and complexity, downloading and verifying the entire blockchain is not suitable for all computing devices.
Third-party internet services called online wallets offer similar functionality but may be easier to use. In this case, credentials to access funds are stored with the online wallet provider rather than on the user's hardware.[102] As a result, the user must have complete trust in the online wallet provider. A malicious provider or a breach in server security may cause entrusted bitcoins to be stolen. An example of such a security breach occurred with Mt. Gox in 2011.[103]
On 1 August 2017, a hard fork of bitcoin was created, known as Bitcoin Cash.[116] Bitcoin Cash has a larger block size limit and had an identical blockchain at the time of fork. On 24 October 2017 another hard fork, Bitcoin Gold, was created. Bitcoin Gold changes the proof-of-work algorithm used in mining, as the developers felt that mining had become too specialized.[117]
The first decentralized cryptocurrency, bitcoin, was created in 2009 by pseudonymous developer Satoshi Nakamoto. It used SHA-256, a cryptographic hash function, as its proof-of-work scheme.[14][15] In April 2011, Namecoin was created as an attempt at forming a decentralized DNS, which would make internet censorship very difficult. Soon after, in October 2011, Litecoin was released. It was the first successful cryptocurrency to use scrypt as its hash function instead of SHA-256. Another notable cryptocurrency, Peercoin was the first to use a proof-of-work/proof-of-stake hybrid.[16]
Nigel Dodd argues in The Social Life of Bitcoin that the essence of the bitcoin ideology is to remove money from social, as well as governmental, control.[137] Dodd quotes a YouTube video, with Roger Ver, Jeff Berwick, Charlie Shrem, Andreas Antonopoulos, Gavin Wood, Trace Meyer and other proponents of bitcoin reading The Declaration of Bitcoin's Independence. The declaration includes a message of crypto-anarchism with the words: "Bitcoin is inherently anti-establishment, anti-system, and anti-state. Bitcoin undermines governments and disrupts institutions because bitcoin is fundamentally humanitarian."[137][136]

Cameron and Tyler Winklevoss, the founders of the Gemini Trust Co. exchange, reported that they had cut their paper wallets into pieces and stored them in envelopes distributed to safe deposit boxes across the United States.[106] Through this system, the theft of one envelope would neither allow the thief to steal any bitcoins nor deprive the rightful owners of their access to them.[105]
Bloomberg reported that the largest 17 crypto merchant-processing services handled $69 million in June 2018, down from $411 million in September 2017. Bitcoin is "not actually usable" for retail transactions because of high costs and the inability to process chargebacks, according to Nicholas Weaver, a researcher quoted by Bloomberg. High price volatility and transaction fees make paying for small retail purchases with bitcoin impractical, according to economist Kim Grauer. However, bitcoin continues to be used for large-item purchases on sites such as Overstock.com, and for cross-border payments to freelancers and other vendors.[149]

Ethereum's smart contracts are based on different computer languages, which developers use to program their own functionalities. Smart contracts are high-level programming abstractions that are compiled down to EVM bytecode and deployed to the Ethereum blockchain for execution. They can be written in Solidity (a language library with similarities to C and JavaScript), Serpent (similar to Python, but deprecated), LLL (a low-level Lisp-like language), and Mutan (Go-based, but deprecated). There is also a research-oriented language under development called Vyper (a strongly-typed Python-derived decidable language).

Most cryptocurrencies are designed to gradually decrease production of that currency, placing a cap on the total amount of that currency that will ever be in circulation.[25] Compared with ordinary currencies held by financial institutions or kept as cash on hand, cryptocurrencies can be more difficult for seizure by law enforcement.[1] This difficulty is derived from leveraging cryptographic technologies.


According to the European Central Bank, the decentralization of money offered by bitcoin has its theoretical roots in the Austrian school of economics, especially with Friedrich von Hayek in his book Denationalisation of Money: The Argument Refined,[132] in which Hayek advocates a complete free market in the production, distribution and management of money to end the monopoly of central banks.[133]:22
Bitcoin, along with other cryptocurrencies, has been described as an economic bubble by at least eight Nobel Memorial Prize in Economic Sciences laureates, including Robert Shiller,[144] Joseph Stiglitz,[202] and Richard Thaler.[203][204] Noted Keynesian economist Paul Krugman has described bitcoin as "a bubble wrapped in techno-mysticism inside a cocoon of libertarian ideology",[135] professor Nouriel Roubini of New York University has called bitcoin the "mother of all bubbles",[205] and University of Chicago economist James Heckman has compared it to the 17th-century tulip mania.[204] Former Federal Reserve Chairman Alan Greenspan has also described bitcoin as a "bubble";[206] the investors Warren Buffett and George Soros have respectively characterized it as a "mirage"[207] and a "bubble";[208] while the business executives Jack Ma and Jamie Dimon have called it a "bubble"[209] and a "fraud",[210] respectively.

Transaction fees for cryptocurrency depend mainly on the supply of network capacity at the time, versus the demand from the currency holder for a faster transaction. The currency holder can choose a specific transaction fee, while network entities process transactions in order of highest offered fee to lowest. Cryptocurrency exchanges can simplify the process for currency holders by offering priority alternatives and thereby determine which fee will likely cause the transaction to be processed in the requested time.
As of May 2018, over 1,800 cryptocurrency specifications existed.[24] Within a cryptocurrency system, the safety, integrity and balance of ledgers is maintained by a community of mutually distrustful parties referred to as miners: who use their computers to help validate and timestamp transactions, adding them to the ledger in accordance with a particular timestamping scheme.[14]

The validity of each cryptocurrency's coins is provided by a blockchain. A blockchain is a continuously growing list of records, called blocks, which are linked and secured using cryptography.[23][26] Each block typically contains a hash pointer as a link to a previous block,[26] a timestamp and transaction data.[27] By design, blockchains are inherently resistant to modification of the data. It is "an open, distributed ledger that can record transactions between two parties efficiently and in a verifiable and permanent way".[28] For use as a distributed ledger, a blockchain is typically managed by a peer-to-peer network collectively adhering to a protocol for validating new blocks. Once recorded, the data in any given block cannot be altered retroactively without the alteration of all subsequent blocks, which requires collusion of the network majority.
In Charles Stross' 2013 science fiction novel, Neptune's Brood, the universal interstellar payment system is known as "bitcoin" and operates using cryptography.[236] Stross later blogged that the reference was intentional, saying "I wrote Neptune's Brood in 2011. Bitcoin was obscure back then, and I figured had just enough name recognition to be a useful term for an interstellar currency: it'd clue people in that it was a networked digital currency."[237]
The unit of account of the bitcoin system is a bitcoin. Ticker symbols used to represent bitcoin are BTC[b] and XBT.[c][76]:2 Its Unicode character is ₿.[1] Small amounts of bitcoin used as alternative units are millibitcoin (mBTC), and satoshi (sat). Named in homage to bitcoin's creator, a satoshi is the smallest amount within bitcoin representing 0.00000001 bitcoins, one hundred millionth of a bitcoin.[2] A millibitcoin equals 0.001 bitcoins; one thousandth of a bitcoin or 100,000 satoshis.[77]
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