# Features of Cryptographic Hash Function

A cryptographic hash function has the following properties:

**Deterministic:**An input A will always have the same output h(A) no matter how many times you parse it through the same hash function.**Quick Computation:**A function should return a hash of an input as quickly as possible.**Pre-Image resistance:**Given h(A) which is an output of a hash function, it should be infeasible to determine input A.**Collision resistance:**Given two inputs A and B and their hash outputs h(A) and h(B) it should be infeasible for h(A) = h(B).**Small changes:**in the input should drastically affect the output of the hash function.**Puzzle Friendly:**For every hash output Y and an input x. It is infeasible to find a value k, which will result in h(k|x) = Y.