Bitcoin

Bitcoin (₿) is a cryptocurrency and worldwide payment system.It is the first decentralized digital currency, as the system works without a central bank or single administrator.These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto[]and released as open-source software in 2009.Bitcoins are created as a reward for a process known as mining. They can be exchanged for other currencies,products, and services. As of February 2015, over 100,000 merchants and vendors accepted bitcoin as payment.[13] Research produced by the University of Cambridge estimates that in 2017, there were 2.9 to 5.8 million unique users using a cryptocurrency wallet, most of them using bitcoin.

The word bitcoin first occurred and was defined in the white paper that was published on 31 October 2008. It is a compound of the words bit and coin.The white paper frequently uses the shorter coin.

There is no uniform convention for bitcoin capitalization. Some sources use Bitcoin, capitalized, to refer to the technology and network and bitcoin, lowercase, to refer to the unit of account. The Wall Street Journal, The Chronicle of Higher Education, and the Oxford English Dictionary advocate use of lowercase bitcoin in all cases, a convention followed throughout this article.

Units

The unit of account of the bitcoin system is a bitcoin. Ticker symbols used to represent bitcoin are BTC and XBT.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. A millibitcoin equals 0.001 bitcoins, one thousandth of a bitcoin or 100,000 satoshis.

Symbol

This was standardized in version 10.0 in June 2017. As with most new symbols, font support is very limited. Typefaces supporting it include Horta.

History

On 18 August 2008, the domain name "bitcoin.org" was registered.[_] In November that year, a link to a paper authored by Satoshi Nakamoto titled Bitcoin: A Peer-to-Peer Electronic Cash System[] was posted to a cryptography mailing list.Nakamoto implemented the bitcoin software as open source code and released it in January 2009 on SourceForge. The identity of Nakamoto remains unknown.

In January 2009, the bitcoin network came into existence after Satoshi Nakamoto mined the first ever block on the chain, known as the genesis block.Embedded in the coinbase of this block was the following text:

The Times 03/Jan/2009 Chancellor on brink of second bailout for banks.

The receiver of the first bitcoin transaction was cypherpunk Hal Finney, who created the first reusable proof-of-work system (RPOW) in 2004.Finney downloaded the bitcoin software the day it was released, and received 10 bitcoins from Nakamoto.Other early cypherpunk supporters were Wei Dai, creator of bitcoin predecessor b-money, and Nick Szabo, creator of bitcoin predecessor bit gold.

In the early days, Nakamoto is estimated to have mined 1 million bitcoins. In 2010, Nakamoto handed the network alert key and control of the Bitcoin Core code repository over to Gavin Andresen, who later became lead developer at the Bitcoin Foundation. Nakamoto subsequently disappeared from any involvement in bitcoin.Andresen stated he then sought to decentralize control, saying: "As soon as Satoshi stepped back and threw the project onto my shoulders, one of the first things I did was try to decentralize that. So, if I get hit by a bus, it would be clear that the project would go on." This left opportunity for controversy to develop over the future development path of bitcoin.

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Bitcoin cash

Bitcoin Cash is a cryptocurrency. In mid-2017 the developers, not content with the Segregated Witness feature, implemented a change to the bitcoin code. The change, called a hard fork, took effect on August 1, 2017.As a result, the bitcoin ledger called the blockchain and the cryptocurrency split in two. At the time of the fork anyone owning bitcoin was also in possession of the same number of Bitcoin Cash units.

In May 2017, bitcoin transactions took up to four days to complete. In order to speed transactions, users could pay a transaction fee, which at the end of 2017 averaged about $28. The delay and especially the fees made bitcoin impractical for everyday use to make small purchases.

Idea forms Edit

Up until July 2017, bitcoin users maintained a common set of rules for the cryptocurrency. On July 20, 2017 at block height 476768 Bitcoin Improvement Proposal (BIP) 91 was locked in (i.e. scheduled to activate at block height 477120). It was designed to reject blocks created by miners not supporting Segregated Witness (SegWit).

Some members of the bitcoin community felt that adopting BIP 91 without increasing the block-size limit favored people who wanted to treat bitcoin as a digital investment rather than as a transactional currency and devised a plan to increase the number of transactions its ledger can process by increasing the block size limit to eight megabytes.

The Bitcoin Cash name was originally proposed by Chinese mining pool ViaBTC.

Development Edit

The first implementation of the Bitcoin Cash protocol called Bitcoin ABC was revealed by Amaury "Deadal Nix" Séchet at the Future of Bitcoin conference in Arnhem, Netherlands. Subsequently, Bitcoin Unlimited made its first release of Bitcoin Cash compatible software, named BUCash and Bitcoin XT also released before the Bitcoin Cash fork.This meant that 3 full node clients were available before the Bitcoin Cash hard fork on August 1, 2017.

These clients implemented the following changes from bitcoin:

Increase maximum block size to 8 megabytes.
Modification of the transaction signature hashing algorithm. This provides replay protection for Bitcoin Cash transactions against the bitcoin chain.
Replaced the original bitcoin difficulty adjustment algorithm (a difficulty adjustment every 2016 blocks), with the new Emergency Difficulty Adjustment (EDA) algorithm. EDA was intended to allow difficulty to more quickly respond to drastic drops in hashrate presumed to occur immediately post fork.

Launch Edit

Upon launch, Bitcoin Cash inherited the transaction history of the bitcoin cryptocurrency on that date, but all later transactions were separate. Block 478558 was the last common block and thus the first separate Bitcoin Cash block was 478559. Bitcoin Cash cryptocurrency wallets started to reject bitcoin blocks and bitcoin transactions after 13:20 UTC, August 1, 2017 because it used a timer to initiate a fork. One exchange started Bitcoin Cash futures trading at 0.5 BTC on July 23; the futures dropped to 0.1 BTC by July 30. Market cap appeared since 23:15 UTC, August 1, 2017.Per the coinmarketcap.com site, the price of BTC on August 1, 2017 was USD$2,718.26[] and the price of BCH was USD$380.01, which suggests the BCH split ratio to be 0.12265. The launch of Bitcoin Cash has created an ideological divide over which chain is the true bitcoin.

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