By fluctuating the voltage to the CPU such that it generated a single hardware error per clock cycle, they found that they could cause the server to flip single bits of the private key at a time, allowing them to slowly piece together the password. With a small cluster of 81 Pentium 4 chips and 104 hours of processing time, they were able to successfully hack 1024-bit encryption in OpenSSL on a SPARC-based system, without damaging the computer, leaving a single trace or ending human life as we know it.

Clever ...