-----BEGIN PGP SIGNED MESSAGE----- On Sun, 14 Apr 1996, Jack Mott wrote:
In Applied Crypto, it talks about thermodynamic limitations of brute force attacks. I did some calculations and it looks like it will take, given a perfectly effecient computer, the combined energy of 509,485,193 average supernovas to brute force a 256 bit key. I was just wondering if there are any theoretical ways around this. I am just talking about plain brute force here, not attacking other weaknesses.
I doubt it. This calculation is based on the minimum amount of energy needed to invert a bit. The amount of energy is a function of the temperature, so a brute force attack might take much less energy several billion years hence, since the universe will cooled off more. There only way for there to be any way around this, is if a way was found to lower the termperature to near absolute zero consuming a very little amount of energy, or if some way was found to invert a bit using less energy than is currently believed (very doubtfull). Of course, if P=NP, then brute-force attacks will be pointless. - -- Mark =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= markm@voicenet.com | finger -l for PGP key 0xf9b22ba5 http://www.voicenet.com/~markm/ | bd24d08e3cbb53472054fa56002258d5 "The concept of normalcy is just a conspiracy of the majority" -me -----BEGIN PGP SIGNATURE----- Version: 2.6.3 Charset: noconv iQCVAwUBMXFCPbZc+sv5siulAQF2jAP9GgSk+YqNjcnyThzs6ow1Ecyp60iK0kiE Y9RMqLtdwpMv2Jx10KigDsyOvQrM0+W/RJ3Q2Zka+VF4aBT82z5NcbUvzEG4Y1iT t12PZF8rhFgxNB+jNOOCxS0BYRcFAC3epZ050+gRdtOenLLNsczyrXJN+fMyaTAf gnCis3s1n1o= =Rvcm -----END PGP SIGNATURE-----