How immutability works

Cryptographic hashing: Each block contains a unique cryptographic hash generated from its data. This hash acts as a digital fingerprint for that specific block.

Chaining blocks: Each new block also includes the hash of the block that came before it, creating a chronological chain.

Tamper detection: If someone tries to alter the data in an old block, its hash will change. Because that hash is included in the next block, the link will be broken, immediately signaling that the chain has been tampered with.

Network consensus: To successfully change a block, an attacker would need to re-calculate the hashes for all subsequent blocks and gain control of a majority of the network's processing power (a 51% attack), which is extremely difficult.

Why immutability is important

Trust and integrity: It ensures that the history of transactions is accurate and can be trusted because it cannot be changed by any single entity.

Security: It makes the blockchain highly resistant to fraud and unauthorized changes.

Transparency and auditability: All transactions are recorded and permanent, making it easy for auditors to verify and scrutinize the history of transactions.

Decentralization: It allows the network to function as a shared, distributed ledger where no single party can manipulate the data.