Example C program that shows how to use multicores to brute-force your way through a hash space if you know credit card numbers are used. Modify the Makefile to point to your platform's CUDA install. On OSX the libraries are "fat binaries" and contain the 64 bit equivalent. On Linux you'll need something like "/usr/local/cuda/lib64".
cchandler/cc-hash-probe
A pthread/CUDA example of how to probe a hash space if you know credit cards are involved
C