How Does Cryptography Ensure Immutability?

Immutability is ensured through the use of cryptographic hash functions and digital signatures. Each block contains a hash of the previous block, creating a chronological and tamper-proof chain.

Changing any data in an old block would change its hash, which would then invalidate the hash stored in the next block, and so on. This domino effect means an attacker would have to recalculate the hashes for all subsequent blocks, a computationally impossible task on a large network.