In my article " Blockchain technology " I explained about blockchains, and in this article I would like to share some examples of how blockchain chains can diverge.
Soft forks and hard forks
A split in the blockchain chain is called a Forks When a blockchain chain splits, it is called a "split block", and when the split block is "compatible with the old and new versions, and the new version of the block is still valid in the old version", it is called a "split block". Soft forks A soft fork is only a compatible block. A soft fork is only a compatible specification change, so the divergences will eventually converge.
On the other hand, incompatible branching from one block to another due to a change in the blockchain's own specifications is known as Hard fork In this case, the chain that diverges is not compatible with the previous one. In this case, the diverged chain is incompatible with the previous one. A hard fork is a permanent split in the blockchain, as the old and new versions are incompatible and will not merge again. This change needs to be done carefully, as the rules in the old version will be invalid in the new version.
A hard fork is basically a split in the development community in order to solve a problem with the blockchain in question, but a split in the community can also lead to a hard fork. This is the case with Ethereum, for example, where a hard fork occurs when a virtual currency is created that is separate from the previous version of the blockchain, i.e. it splits into two currencies.
This means that all users of the virtual currency will have to be aware of the choice of which blockchain to use after the split, as the transition from the old version to the new version will not be compatible with the previous version, nor will it be possible to share previous balances. This means that all users of the virtual currency will have to be aware of the choice of which blockchain to use after the split.
Examples of Ethereum hard forks
Ethereum underwent a hard fork in 2016, splitting into Ethereum (ETH) and Ethereum Classic (ETC). This hard fork was caused by a hacking incident known as The DAO.
The DAO case was the theft of approximately $5 billion worth of Ethereum (ETH) in June 2016 after exploiting a problem with the system implemented as a smart contract on Ethereum.
Both a soft fork and a hard fork were considered in response to this incident, but a hard fork was implemented as a result.
First, a soft fork was considered to freeze the wallet that stole the ETH so that it could not be withdrawn. Of course, since it is a soft fork, the chain is compatible before and after the fork, but since it is frozen, it is impossible to retrieve the stolen ETH.
ON THE OTHER HAND, BY USING A HARD FORK, WHICH STARTS FROM A CERTAIN BLOCK AND CAUSES INCOMPATIBLE BRANCHES DUE TO A CHANGE IN THE BLOCKCHAIN'S OWN SPECIFICATIONS, A METHOD OF "REVERTING TO THE STATE BEFORE THE ETH WAS STOLEN", THAT IS, "CREATING ANOTHER BLOCKCHAIN FROM THE STATE BEFORE THE ETH WAS STOLEN, SO THAT THE FACT THAT THE ETH WAS STOLEN ITSELF IN OTHER WORDS, BY CREATING A NEW BLOCKCHAIN FROM THE PRE-STOLEN STATE, WE CAN PRETEND THAT THE ETH WAS NEVER STOLEN.
AS A RESULT, THE HARD FORK WAS CHOSEN, BUT THERE WERE NATURALLY SOME PEOPLE WHO WERE AGAINST THE HARD FORK, AND AS A RESULT, THERE ARE TWO VERSIONS OF ETHEREUM: ETHEREUM CLASSIC (ETC), WHICH CONTINUES THE PREVIOUS STATUS, AND ETHEREUM (ETH), WHICH IS THE NEWLY FORKED SIDE. (ETH).
Incidentally, this incident was caused by a software vulnerability, not a vulnerability in Ethereum itself, but a vulnerability due to an implementation error in a blog called "The DAO", which is implemented as a smart contract of Ethereum.
Smart contracts" refers to the automation of contracts in the blockchain, from the confirmation of the terms and conditions to the execution of the contract by a program. More details will be provided at another time.
Hard forks and soft forks, which are used to make major changes to blockchain specifications, are turning points in blockchains that are major events. It is important to understand the concepts discussed above, as they are unavoidable when studying the history of blockchain and it is likely that the topic of forks will continue to appear in the future.