Cryptographic hashes produce a fixed-size and unique hash value from variable-size transaction input. The SHA-256 computational algorithm is an example of a cryptographic hash.

A cryptographic hash function is an algorithm that transforms an input (or "message") into a fixed-size string of bytes, typically a hash value or digest. It is designed to be a one-way function, meaning the original input cannot be easily reconstructed from the hash. Cryptographic hash functions are fundamental to security practices like password hashing, digital signatures, and data integrity verification.

Key characteristics include determinism (the same input always produces the same output), collision resistance (difficult to find two different inputs with the same hash), and resistance to pre-image attacks (difficult to reverse-engineer the input from the hash). Common examples include SHA-256 and MD5, though the latter is no longer considered secure for cryptographic purposes.