Is blockchain actually immutable?

ParallelChain Lab
2 min readSep 14, 2022

If you’re part of the blockchain world, you‘ve probably heard at numerous points that blockchain is immutable.

What do people mean when they say this?

They’re referring to the fact that transactions records, all the way to the beginning of the blockchain in question, are unmodifiable or changeable.

While this is true, the extent to which blockchain is immutable varies depending on a number of different factors.

In what ways can blockchain be mutable?

There are a number of ways that blockchain could be mutable, although incredibly difficult and costly.

Private (permissioned) blockchains, used commonly by enterprises, tend to be smaller in size and therefore are easier to be manipulated or attacked. This has hindered institutional adoption, as it puts companies’ data privacy and security at risk.

On the other hand, in proof-of-stake public blockchains, where transactions are verified by validators who have staked a certain number of their tokens, the amount of tokens they are staking could impact the level of security of the blockchain because validators with larger holdings typically have higher influence on transaction verification, and can therefore collude to modify the protocol to their benefit.

Small-scaled public blockchains are also vulnerable. Research conducted by New York University found that the cost of attacking the Litecoin blockchain for an hour is about $39,018, which can easily be recouped if enough high-value transactions are tapped into and reversed.

Proof-of-Immutability (PoIM):

Proof-of-immutability is a new type of blockchain infrastructure solution developed and patented by ParallelChain that enhances the privacy and scalability of the proof-of-stake consensus mechanism.

It allows participants of the blockchain network to inspect the trustworthiness of one another’s data through proving immutability at any point in history, not just the last block in the chain.

With proof-of-immutability, participants are able to check whether the chain has been manipulated or a piece of record has been altered, without accessing the database and private information. This creates an environment that is highly secure, private, fast and compliant — all while maintaining the goal of decentralization.

Proof-of-immutability has been deployed in ParallelChain Private, and will be integrated into ParallelChain Mainnet in the future to enhance data privacy for institutional adoption.