Immutable Meaning

May 28, 2023 | Updated Oct 4, 2023

The term “immutable” in the context of a blockchain implies that the data or ledger is permanent and tamper-proof, and its history cannot be modified or changed after its creation.

What is Immutable in Blockchain?

Immutability is one of the core, defining properties of a blockchain. It is a trait in which something, once created, cannot be changed. Immutable transactions are an essential aspect of blockchains.

Immutable transactions mean that the transactions or data stored in the blockchain are impossible for anyone (government, organizations, or individuals) to manipulate, modify, or falsify.

Immutability, as one of the main features of blockchain technology, is achieved through a method called cryptographic hashing that converts plaintext of any size into a unique string of text of a fixed length.

For instance, a plaintext input like the term “immutability” can be converted to produce a 64-character value, called a hash value, that is irreversible. The value for this term will be: c2dd567a7abf29bce640cbbab5a07c9c96ca8a147038798bc2e8a6443bdeb750

Since participating nodes need to agree on the legitimacy of a transaction before approving it, immutability serves as a key element in enabling data integrity in blockchain technology. Once data is added to the blockchain, the records cannot be retroactively altered without changing all the subsequent blocks in the network.

Benefits of Immutability in Blockchain Technology

The key benefits of immutability in blockchain technology are related to data integrity, security, fraud detection and prevention, and auditing. Immutability:

Makes the auditing process easier and cost-efficient, since auditors can rely on the authenticity and legitimacy of the data source (blockchain). This is coupled with the indelible, permanent, and indisputable nature of blockchain transaction history.
Facilitates a verifiable, shared source of truth.
Minimizes the risk of any data modifications, since it would require all the participating nodes in the network to verify and accept the change.
Protects data integrity by preventing invalid transactions.

While immutability is one of blockchain’s core benefits, it doesn’t make blockchains resilient to vulnerabilities like double spending or a 51% attack. While the odds are low, a malicious actor could gain control of a majority of a network’s hash rate to alter data or transactions.