"In their research paper titled RSA Key Extraction via Low-Bandwidth Acoustic Cryptanalysis, Daniel Genkin, Adi Shamir and Eran Tromer et al. present a method for extracting decryption keys from the GnuPG security suite using an interesting side-channel attack. By analysing the acoustic sound made by the CPU they were able to extract a 4096-bit RSA key in about an hour (PDF). A modern mobile phone placed next to the computer is sufficient to carry out the attack, but up to four meters have been successfully tested using specially designed microphones." -- source: http://it.slashdot.org/story/13/12/18/2122226 Cheers, Peter -- Peter Reutemann, Dept. of Computer Science, University of Waikato, NZ http://www.cms.waikato.ac.nz/~fracpete/ Ph. +64 (7) 858-5174