Re: key bit lengths
At 6:21 PM 4/14/96, Mark M. wrote:
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.
A late April Fool's joke, methinks? Arguing that in "several billion years" the "temperature" of the universe will have anything to do with computation....well, your physics is all wrong. The approximate figure, kT, for the minimum energy in a conventional bit flip, can be reduced by simple cooling. Not a problem. And what the so-called "average temperature" of the Universe may be in, say, 10 billion years, will not affect computation. Fusion will still occur, stars will still burn, sunshine will still produce heat. And so on. --Tim May Boycott "Big Brother Inside" software! We got computers, we're tapping phone lines, we know that that ain't allowed. ---------:---------:---------:---------:---------:---------:---------:---- Timothy C. May | Crypto Anarchy: encryption, digital money, tcmay@got.net 408-728-0152 | anonymous networks, digital pseudonyms, zero W.A.S.T.E.: Corralitos, CA | knowledge, reputations, information markets, Higher Power: 2^756839 - 1 | black markets, collapse of governments. "National borders aren't even speed bumps on the information superhighway."
-----BEGIN PGP SIGNED MESSAGE----- On Sun, 14 Apr 1996, Timothy C. May wrote:
A late April Fool's joke, methinks? Arguing that in "several billion years" the "temperature" of the universe will have anything to do with computation....well, your physics is all wrong.
The approximate figure, kT, for the minimum energy in a conventional bit flip, can be reduced by simple cooling. Not a problem. And what the ^^^^^^^^^^^^^^ so-called "average temperature" of the Universe may be in, say, 10 billion years, will not affect computation. Fusion will still occur, stars will still burn, sunshine will still produce heat. And so on.
I'm a little rusty on physics, but it seems to me that you are forgetting the fact that energy needs to be used in order to lower the temperature below the temperature of background radiation. A lot of energy. I don't have any numbers available, but I think that it would takes much more energy to invert a bit where energy has to be used to keep the temperature below the temperature of background radiation then to invert the bit at temperatures greater than or equal to the temperature of background radiation. Brute-force cracking will take less energy when the universe has cooled off more (assuming it does implode first). - -- 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 iQCVAwUBMXKwFbZc+sv5siulAQFv8wP/aiC93myrk4swZYJ2ocCVsvy/+HAJyu/9 ujQl910QUrs27BfkHfiHnVbTYUWQycEPxe0o4b6KGOJwkJ2TssMpuVY5TE+35GKL a0fdaaKUxb2DDXWvr6jyOi682dLzx0gqvMo+gWXSKccFk8U5KcHZEh9TL53CopvP 2KzTet/lB0o= =ef7j -----END PGP SIGNATURE-----
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