Q17Information Security Systems
Question
4 marks
Explain the properties of a secure cryptographic hash function.
Answer
Cryptographic hash functions must be deterministic, quick, and collision-resistant.
A secure cryptographic hash function takes an input of arbitrary size and outputs a fixed-size string (hash value). Key properties include Pre-image resistance (computationally infeasible to find the input from the hash), Second pre-image resistance (infeasible to find a different input that hashes to the same value as a given input), and Collision resistance (infeasible to find any two distinct inputs that produce the same hash). Minor changes in input must drastically change the output (Avalanche effect).