Bitcoin Hard Forks History
Hard Fork
Hard forks refers to the underlying blockchain of a digital currency forks into 2 chains initially due to the underlying rules change. After a hard fork, the blockchain conforms to the revised (upgraded) rules is only considered and accepted by nodes that support the new rules, whereas the original blockchain conforms to the original rules is only recognized by nodes that support the original rules. That is, the new rules are not compatible with the old existing rules. Think of hard fork as a possible permanent divergence of a block chain that might result in splitting a chain into two, thus producing an extra new coin for every existing coin.
Why Hard Fork
Digital currency build upon protocol and rules.
Rule, what rule?
For example, original Bitcoin protocol/rule is capable of processing 3-7 transactions per second, which is way too low for Bitcoin to become a transaction currency. Therefore, they were many thoughts to solve this 'problem'.
Bitcoin has other 'problems' too. For another example, wouldn't it be better if miners can mine coins using GPU and not necessary need to have ASIC based mining hardware? In order to 'solve' this particular 'problem', new rules were proposed to change the mining algorithm to not in favor of miners using ASICs.
To date, proposals were put in action to solve these 'problems' involve increasing block size limitation (e.g. BCH, B2X), or segregating some non-transactoin data from the block (e.g. Segregated Witness).
Hardfork that Succeeded
There were many hard forks in Bitcoin history. Some of them failed for a reason or two - lack of consequent support, buggy software, When a hard fork failed to go on, the new chain wouldn't last too long after the split. For example, Bitcoin Unlimited, Bitcoin Classic, Bitcoin XT [1] are among the dead list.
Ever wonder what successful hard forks had happened in Bitcoin's history since its inception? We compile a list of successful hard forks and upgrade events and the attributes of the new coin each fork/upgrade introduced.
Hard forks refers to the underlying blockchain of a digital currency forks into 2 chains initially due to the underlying rules change. After a hard fork, the blockchain conforms to the revised (upgraded) rules is only considered and accepted by nodes that support the new rules, whereas the original blockchain conforms to the original rules is only recognized by nodes that support the original rules. That is, the new rules are not compatible with the old existing rules. Think of hard fork as a possible permanent divergence of a block chain that might result in splitting a chain into two, thus producing an extra new coin for every existing coin.
Why Hard Fork
Digital currency build upon protocol and rules.
Rule, what rule?
For example, original Bitcoin protocol/rule is capable of processing 3-7 transactions per second, which is way too low for Bitcoin to become a transaction currency. Therefore, they were many thoughts to solve this 'problem'.
Bitcoin has other 'problems' too. For another example, wouldn't it be better if miners can mine coins using GPU and not necessary need to have ASIC based mining hardware? In order to 'solve' this particular 'problem', new rules were proposed to change the mining algorithm to not in favor of miners using ASICs.
To date, proposals were put in action to solve these 'problems' involve increasing block size limitation (e.g. BCH, B2X), or segregating some non-transactoin data from the block (e.g. Segregated Witness).
Hardfork that Succeeded
There were many hard forks in Bitcoin history. Some of them failed for a reason or two - lack of consequent support, buggy software, When a hard fork failed to go on, the new chain wouldn't last too long after the split. For example, Bitcoin Unlimited, Bitcoin Classic, Bitcoin XT [1] are among the dead list.
Ever wonder what successful hard forks had happened in Bitcoin's history since its inception? We compile a list of successful hard forks and upgrade events and the attributes of the new coin each fork/upgrade introduced.
| Date | Name | Block Size | Mining Algorithm | Mining Hardware | Segwit | Difficult Adjustment | Max Supply | Amount Encrypted |
|---|---|---|---|---|---|---|---|---|
| 2009/1/3 | Bitcoin (BTC) | 1M | SHA256 | ASIC | Y | 2 Weeks | 21 Million | N |
| 2017/8/1 | Bitcoin Cash (BCH) | 8M | SHA256 | ASIC | N | 2 Weeks + EDA | 21 Million | N |
| 2017/10/23 | Bitcoin Gold (BTG) | 1M | Equihash | GPU | Y | 10 Minutes (every block) | 21 Million | N |
| 2017/11/16 (cancelled) | SegWit2x (B2X) | 2M | SHA256 | ASIC | Y | 2 Weeks | 21 Million | N |
| 2017/11/24 | Bitcoin Diamond (BCD) | 8M | OPTIMIZED X13 | GPU | Y | 2 Weeks | 210 Million | Y |
| 2018/5/15 | Bitcoin Cash (BCH) | 32M (was 8M) [3] | SHA256 | ASIC | N | 2 Weeks + EDA | 21 Million | N |
| 2018/11/15 | Bitcoin SV (BSV) | 128M | SHA256 | ASIC | N | 21 Million | N |
Among the above listed coins in Bitcoin family, BTC and BCH both ranked high in terms of market capital. BTG is quite new and is not yet widely supported by exchanges, and B2X was cancelled after it had got big players like Coinbase promises to support it. Bitcoin Diamond (BCD) is very new.
There were many other fork attempts in the past [2]. However, not all of them survived.
UPDATE:
As of 2017/11/8, the planned hard fork of Bitcoin SegWit2x (B2x) had been called off. [1]
There were many other fork attempts in the past [2]. However, not all of them survived.
UPDATE:
As of 2017/11/8, the planned hard fork of Bitcoin SegWit2x (B2x) had been called off. [1]
