Immutable

What Is Immutable?

Immutable is the core characteristic of blockchain. The term ‘immutable’ signifies that data cannot be modified or changed by anyone after its creation.

In a blockchain network, immutability is essential because all nodes must agree on the validity of the data before passing it on. The primary purpose of using blockchain as a distributed ledger technology (DLT) is to ensure that no individual entity can make changes to records once they are added to the blockchain.

Immutable refers to the ability to record transactions, such as contracts, sales, purchases, etc., in a way that the data in those records cannot be retroactively altered without changing all subsequent blocks and colluding with the network.

How Blockchain Is Made Immutable?

Cryptographic hashing is what ensures the immutability of blockchain.

Hashing is an encryption technique that takes any length of plaintext input and generates a unique hash value. Regardless of the input properties, hashes are always of a fixed length.

The hashing algorithm is simple but difficult to reverse. For example, applying the SHA-256 hashing algorithm to the phrase “the quick brown fox jumps over the lazy dog” would result in a 256-bit (32 characters) hexadecimal number like “9e107d9d372a5dcea0c3f78f5340d8d4”. Applying this algorithm to any other text string, such as a password, will always produce the same output (a 32 character hexadecimal number).

The hash can be used as a digital signature for ensuring data integrity.

When data is sent over the network, its hash value can be used as a fingerprint. Upon receiving the same data, its hash can be computed and compared to the original fingerprint. If they don’t match, it indicates that someone tampered with the data during transit.

It’s important to note that immutability doesn’t guarantee that data cannot be altered. Its purpose is to ensure that no data or record on a blockchain can be changed without consequences.

Benefits of Immutability

The benefits of immutability are associated with security, data integrity, easy auditing, and fraud prevention on blockchains.

• In a traditional database system, if someone gains access to the data, they can corrupt or destroy it. In a blockchain, any changes to data require the consensus of all network nodes. This eliminates the risk of data loss and contributes to the immutability of the blockchain.
• Blockchain immutability ensures the protection of data integrity. The integrity of a chain can be verified by recalculating the hash value. Any discrepancy between the block data and its corresponding hash value indicates invalid transactions.
• Immutability allows organizations to maintain an indisputable ledger, which helps prevent complications during audits.

Thanks to cryptographic hashing, blockchain achieves immutability. Any changes or alterations made to a chain will disrupt the entire network.