Abstract or Summary:
This paper presents a hardware architecture for UNIX password cracking using Hellman’s time-memory trade-off; it is the first hardware design for a key search machine based on the the rainbow variant proposed by Oechslin. We estimate that an FPGA implementation of the function can run at 17.5 million password tests/second on a Virtex-4. Our design targets passwords of length 48 bits (out of 56). This means that with 16 FPGAs the precomputation for one salt takes about 11 days, resulting in a storage of 56 Gigabyte. Recovering an individual password requires a few minutes.