SHA-crypt analysis SHA-crypt hashes are decent (albeit not a technical improvement), especially the flavor based on SHA-512 Uses 64-bit machine words; not SIMD, though SHA-512 is not as GPU-friendly as e.g. MD5, yet is reasonable to attack on current GPUs (2012) sha512crypt at default rounds=5000 can be attacked at ~12000 c/s on NVIDIA GTX 580 with John the Ripper (code by Claudio Andre) or hashcat, or at ~32500 c/s with hashcat on HD 6990 (two GPUs) bcrypt at "$2a$08" (256 iterations), which is default on some systems, can be attacked at ~680 c/s on AMD FX-8120 3.1 GHz (combined speed for 8 threads) with John the Ripper; no speedup from GPUs yet (e.g. HD 7970 and 6990 achieve CPU-like speeds at bcrypt)