You could probably do that relatively safely with bit operations, but I expect to be proved wrong. Something like this should work: /* Swap char for uint<

You could probably do that relatively safely with bit operations, but I expect to be proved wrong. Something like this should work: /* Swap char for uint<register_size> for speed */ #define CMP_TYPE char /* Assuming char* sha256(char* input); */ CMP_TYPE* input_hash=(CMP_TYPE*) sha256(input); CMP_TYPE* token_hash=(CMP_TYPE*) sha256(token); /* Precomputed? */ /* max_pos=32 for char on most systems */ int max_pos=256 >> (3 + sizeof(CMP_TYPE)); char cmp=0; for (int i=0;i<max_pos;i++) { cmp = cmp | (token_hash[i] ^ input_hash[i]); } return (cmp != 0); The reason for the CMP_TYPE #define is so that you can optimise the comparison by replacing char with uint32 or uint64.