What is Bitcoin fork?

A fork is a modification of the computer code governing the Blockchain. There are two types of forks easily distinctive. The first version, the most widespread, is a soft fork. The second is called a hard fork.

Vintage Fork pencil drawn

The Blockchain is governed by consensus protocols. All decisions are made collectively by vote. The Bitcoin community is an open community with a place for all, without distinction. Its membership is done by downloading an open source protocol software. All these members are grouped around a code that they must respect under penalty of being out of sync, ie excluded from the network.

However, this code is not something immutable or engraved in stone. It is scalable, if approved by the network. The consensus is a necessity to maintain unity, guarantee the legitimacy of transactions and value all the different coins or tokens. The same is true for traditional fiduciary currencies. They have only a numerical value which is justified by the fact that everyone is ready to accept it as a means of payment. If it’s not, the network effect comes into play. Subnetworks considered as useless are bound to disappear, contrary to the changes deemed to be a service of general economic interest.

Each participant is free to make a proposal. However, to be accepted, it must be approved by a minimum of 75% of the network, in general (the more, the better). Thanks to this method, it is extremely complicated for an individual to propose a modification with a personal interest only because there is no government or central bank to impose his authority, which reduces to nothing Corruption attempts. In addition, all participants are spread over the four corners of the globe, speaking different languages and having different cultures. That means a modification must necessarily have a collective interest to have a chance to be accepted.

The expression of hard fork or soft fork is in no way related to the approval rate received by the modification, it depends solely on the nature of the modification:

A soft fork is a retro-compatible modification of the rules intended to make them more stringent. This becomes effective in case the majority of miners accept this change. Note that a soft fork is backward-compatible. This term means that old nodes will recognize the new blocks as valid. All new blocks must necessarily respect new rules to be validated. Those who will not be deemed compliant will no longer be validated by miners and therefore will be automatically excluded.

Bitcoin Forks

Thus, the use of the word soft indicates the compromise and insists that the network itself is not divided. There is no obligation to update the software and the minority that was against this change may continue to apply the old rules, provided that they do not conflict with the new requirements.

Conversely, a hard fork is a major protocol modification that leads to the division and the obligation for all participants to update or upgrade their software if they want to continue using this blockchain. Here, no backward-compatibility since the rules does not apply to the previous blocks.

The main advantage here lies in the fact that the code in its entirety can be changed (nb: old rules will no longer apply). We can change governance rules, rewrite transaction history and how to send and receive its bitcoins. Everything is possible. However, a hard fork is very constraining for all participants and it is therefore very difficult to obtain a broad consensus, resulting in a pure split and the creation of a parallel blockchain.

The success or failure of a hard fork lies mainly in the degree of conflict it generates when it is created. If the division is large, the network effect will quickly lead to its loss due to a lack of confidence. The value of a good lies first and foremost in the trust placed in it, and investors, even the most fervent, will always look for security from the network and the safest protocol is only the one that creates value.

Bitcoin Forks Timeline Bitcoin Forks Chronology – The Ultimate List of Forks

Hard fork examples:

The first:

The significant first hard fork took place on August 1, 2017. The increase in block size is at the basis of the conflict. A group of developers wishing to return to the original size, that was originally "planned by Satoshi Nakamoto", 32 MB per block, and let the 1MB limit introduced in summer 2010 fall.

The purpose was to fight the growing cost increase and reduce the confirmation time in order to support the growth of user numbers. Indeed, 1 MB per transaction thus limits to 3 the number of transactions per second, which forces the actors wishing to close their transaction in priority to pay a tax estimated in Satoshi / bytes. In 2017, the Segwit solution proposed by the original protocol to help avoid this problem did not get the favors of this group of protesters, resulting in chain split and the creation of Bitcoin Cash (BCH).

The latest:

The last one that took place is important, and once again with Bitcoin Cash. This time, two clans, ABC and SV, argue about the Satoshi Nakamoto's vision. The first of them wishing to instaure smarts contracts in the image of what is done on the Ethereum network, which according to the second actor, would be contrary to the vision of the founding father. This would threaten the stability of Bitcoin Cash.

It should be noted however that in this case, an ego war seems to rage which complicates the analysis of this hard fork.

Table:
Name Symbol Blockchain Fork Date Fork Block Coin Distribution
Bitcoin Cash Fork BCH Bitcoin Tuesday, August 01, 2017 478559 1 BTC = 1 BCH
Bitcoin Clashic Fork BCHC / B Bitcoin Tuesday, August 01, 2017 478558 1 BTC = 1 BCHC / B
Oil BTC Fork OBTC Bitcoin Tuesday, August 01, 2017 498888 1 BTC = 1 OBTC
Bytether Fork BTH Bitcoin Tuesday, August 01, 2017 478558 1 BTC = 1 BTH
Bitcoin Gold Fork BTG Bitcoin Tuesday, October 10, 2017 491407 1 BTC = 1 BTG
Bitcoin Diamond Fork BCD Bitcoin Friday, November 24, 2017 495866 1 BTC = 10 BCD
Bitcore Fork BTX Bitcoin Thursday, November 02, 2017 0 1 BTC = 0.5 BTX
Bitcoin Nano Fork BTN Bitcoin Friday, December 01, 2017 501888 1 BTC = 1000 BTN
Bitcoin Silver Fork BTSI Bitcoin Friday, December 01, 2017 0 1 BTC = 1 BTSI
Super Bitcoin Fork SBTC Bitcoin Tuesday, December 12, 2017 498888 1 BTC = 1 SBTC
BitcoinX Fork BCX Bitcoin Tuesday, December 12, 2017 498888 1 BTC = 10000 BCX
Bitcoin Hot Fork BTH Bitcoin Tuesday, December 12, 2017 498848 1 BTC = 100 BTH
UnitedBitcoin Fork UB Bitcoin Tuesday, December 12, 2017 498777 1 BTC = 1 UB
Bitcoin World Fork BTW Bitcoin Sunday, December 17, 2017 499777 1 BTC = 10000 BTW
Bitcoin Faith Fork BTF Bitcoin Tuesday, December 19, 2017 500000 1 BTC = 1 BTF
Bitcoin Stake Fork BTCS Bitcoin Tuesday, December 19, 2017 499999 1 BTC = 100 BTCS
Lightning Bitcoin Fork LBTC Bitcoin Tuesday, December 19, 2017 499999 1 BTC = 1 LBTC
Bitcoin New Fork BTN Bitcoin Monday, December 25, 2017 501000 1 BTC = BTN
Bitcoin Top Fork BTT Bitcoin Tuesday, December 26, 2017 501118 1 BTC = 1 BTT
Bitcoin File Fork BIFI Bitcoin Wednesday, December 27, 2017 501225 1 BTC = 1000 BIFI
Bitcoin God Fork GOD Bitcoin Wednesday, December 27, 2017 501225 1 BTC = 1 GOD
Bitcoin SegWit2X x11 Fork B2X Bitcoin Thursday, December 28, 2017 501451 1 BTC = 1 B2X
Quantum Bitcoin Fork QBTC Bitcoin Thursday, December 28, 2017 0 1 BTC = 1QBTC
Bitcoin Ore Fork BCO Bitcoin Sunday, December 31, 2017 501949 1 BTC = 1 BCO
BitcoinBoy Fork BCB Bitcoin Sunday, December 31, 2017 501888 1 BTC = 100 BCB
Bitcoin Uranium Fork BUM Bitcoin Sunday, December 31, 2017 0 1 BTC = 1 BUM
Bitcoin Pizza Fork BPA Bitcoin Monday, January 01, 2018 501888 1 BTC = 1 BPA
Bitcoin All Fork BTA Bitcoin Monday, January 01, 2018 0 1 BTC = 1 BTA
Bitcoin Private Fork BTCP Bitcoin Monday, January 01, 2018 0 1 BTC/ZCL = 1 BTCP
Bitcoin Rhodium Fork BTR Bitcoin Wednesday, January 10, 2018 0 1 BTC = 1 BTR
Bitcoin Smart Fork BCS Bitcoin Sunday, January 21, 2018 505050 1 BTC = 100 BCS
BitVote Fork BTV Bitcoin Sunday, January 21, 2018 505050 1 BTC = 1 BTV
Bitcoin Interest Fork BCI Bitcoin Monday, January 22, 2018 505083 1 BTC = 1 BCI
Bitcoin Atom Fork BCA Bitcoin Wednesday, January 24, 2018 505888 1 BTC = 1 BCA
Bitcoin Lite Fork BTCL Bitcoin Tuesday, January 30, 2018 0 1 BTC = 1 BTCL
ClassicBitcoin Fork CBTC Bitcoin Sunday, April 01, 2018 516095 1 BTC = 10000 CBTC
Micro Bitcoin Fork MBC Bitcoin Wednesday, May 30, 2018 525000 1 BTC = 10000 MBC
Bitcoin Zero Fork BZX Bitcoin Sunday, September 30, 2018 0 1 HXX : 1 BTC = 1 BZX
Bitcoin Cash ABC BCHABC Bitcoin Cash Thursday, November 15, 2018 556767 1 BCH : 1 BCHABC
Bitcoin Cash SV BCHSV Bitcoin Cash Thursday, November 15, 2018 556767 1 BCH : 1 BCHSV