What Does Hard And Soft Fork Mean In Blockchain?

By Telos Feed on Altcoin Academy

For the users that have a basic knowledge about blockchain and cryptos, the concepts of the hard and soft fork may be a little intriguing.

Hard fork vs soft fork

A fork, as its name refers, according to Oxford, is “an implement with two or more prongs used for lifting food to the mouth or holding it when cutting,”, in blockchain its similar, because it refers to the creation of a new protocol by the developers (related with the existing blockchain protocol), which represents a new version of the platform. This means that the original version of the platform and the new one can coexist, just as the prongs of a fork.

Many blockchains need to fix some flaws that they might have on the network, that is why it is necessary to fork the chain and make an update. A fork (software development) means rewriting the rules which a BP (or node) must follow in order to validate a block. The full node can accept or reject the new update, in the case that some of the nodes reject these software changes, then the blockchain might split into two different branches (old rules and new rules) and a blockchain fork happens, creating a distinct and separate piece of software. These two branches share the same Genesis Block but if the blockchain community of the full nodes doesn’t make a strong decision about the fork, it may affect negatively the reliability of the chain and decrease the interest of the investors.

To understand better this concept these two definitions are essential:

What is a fork?

Fork

It is when the blockchain has two versions (the old one and the updated one). Also, according to Coindesk, it is “an open-source code modification”

Blockchain Protocol

Codes that define the rules of operations and transactions within the network. Everyone needs to stick with the protocols of each blockchain in order to be part of them.

There are two types of forks: Hard Fork and Soft Fork

Hard Fork vs Soft Fork

Hard Fork

It is a change to a blockchain protocol that is not compatible with older versions. This means that the blocks created with the new rule are not compatible with the blocks created with the old one. If the blocks of the older version continue running, they will have different protocols and information from the new ones, leading into chaos.

In many blockchain cases, the protocols are approved or rejected by a consensus of a majority of 51% of the full nodes (or in some cases BPs). In the case of Telos Blockchain, the consensus is 2/3+1 in the BP voting. To learn more about Telos BPs and Consensus Algorithms Protocols enter our Medium Articles The Blockchain Ecosystem and The Who, What and How of Telos’ Block Producers. According to GoodBlock,

“it is important to note that this is a hard fork in the consensus protocol of the EOSIO software, meaning that EOSIO v.1.8.x cannot interoperate with previous versions without creating forks in the chain.”

Telos is an independent blockchain forked from the same genesis block of EOS; Telos uses their own token (TLOS) to represent de blockchain.

The way it was explained to me was: Sisterchains are independent blockchains that forked from the same genesis block and use their own token to represent their blockchain. An EOS sidechain is an added chain that uses the existing EOS token if, for example, the original chain is at capacity they would spin up a 2nd sidechain for added bandwidth.

In the after mention cases of blockchain consensus, if the 100% of the full nodes accept or reject the new software changes, there will be no blockchain split. When two blockchain protocols run in the same chain, it means that the blockchain has split, this happens when (in the case of some chains), some of the nodes that are not part of the 51% that approved the changes are using the older version.

Example: The implementation of a new rule where the block size was to be increased from 2MB to 5MB, a 3MB block would be recognized by the new version nodes, but it would be rejected by the ones that are based on the old rules.

Soft Fork

Unlike hard forks, soft forks are compatible with older versions. The block created with the new rule is accepted or compatible with the block created in the older version, but not the way around, meaning that it is forward compatible. In the case that 51 % or more of the full nodes approve the soft fork, there will be no blockchain split, but in the case that less than that 51% of the full node still create blocks based on the old rule, the blockchain will split, since the old version is not compatible with the new one.

Example: In this case, if the community of full nodes decides to decrease the block size from 2MB to 500KB, the blocks created in the new rules would reject 2MB blocks, and would build on the previous version (causing a temporary fork).

Hard Fork vs Soft Fork

In conclusion…

Blockchain development it’s not an easy task to understand, but if a user expands its knowledge and its crypto vocabulary each day, he/she would understand smoothly this new technology.

As mentioned above, the two types of forks can affect positively or negatively the reputation of a chain. It is important that all the community of nodes think in the future of their blockchain, by doing this, it is essential that they take a look at the important software changes that the chain needs and make a unanimous decision, in order to not split the blockchain into two protocols, and drive all depower into one chain. Soft Fork is recommended because the old version and the new version of the chain can run together.