What Cryptographic Function Is Primarily Used to Generate Transaction Hashes?

The primary cryptographic function used to generate transaction hashes is a one-way cryptographic hash function, such as SHA-256 for Bitcoin or Keccak-256 for Ethereum. This function takes the entire transaction data as input and produces a fixed-length output string.

The function is deterministic, meaning the same input always yields the same output, but even a tiny change in the input data results in a completely different output, ensuring immutability.