-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 09/09/2013 04:01 PM, Eugen Leitl wrote:
Even cheaper: hang a cheap microphone into a fan exhaust. Noise definitely not white, but certainly more entropy than just looking at lowest bits of A/D.
I've been playing with one of these for a while with one of my netbooks: https://www.sparkfun.com/products/11345 By default, the firmware running in the on-board microcontroller records the time between three successive hits on the 'tube (t1, t2, t3). If (t2 - t1) < (t3 - t2), it prints a 0 to the serial port, else, it prints a 1 to the serial port. Hardly high resolution entropy, but it can be stirred into an entropy pool. New firmware can, of course, be developed using the existing C code as a base. I'm not entirely certain how helpful or useful it is (I have my doubts, to be honest), but if nothing else it's given me cause to do some reading up and try a few small scale experiments. - -- The Doctor [412/724/301/703] [ZS] Developer, Project Byzantium: http://project-byzantium.org/ PGP: 0x807B17C1 / 7960 1CDC 85C9 0B63 8D9F DD89 3BD8 FF2B 807B 17C1 WWW: https://drwho.virtadpt.net/ Your memories are fiction. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlIvYZMACgkQO9j/K4B7F8EkFACffdFMYDo4n4b5o28SVwNGO6DJ CS8An3uWoQfewFYBCmP+1xByr3yDxgH2 =/y/F -----END PGP SIGNATURE-----