[RC5] 128K encryption

Robert Brooks robertb at geocities.com
Fri Nov 28 11:30:52 EST 1997

Here's something I stumbled across on Windows Magazine's online site (from
the Oct '97 issue, I believe):

Even longer, more secure ciphers have recently been cracked using readily
available equipment. Recently, a group of ordinary folks used an ad hoc
network of Pentium-class PCs to crack a 56-bit cipher to win a prize
offered by a prominent encryption software developer. Using idle time on
each machine, they cracked the code in five months. As personal
computers become faster, it will take less time to perform such a feat, and
more computers will have the power to pick apart a 56-bit cipher. 

That's why 64-bit keys are now common in products not intended for
export outside the United States. And programs allowing 128-bit and
longer keys are beginning to appear. Longer keys are harder to crack
because crackers have to sift through more key values before finding the
right one. Just moving from 40- to 64-bit keys multiplies the number of
possible key values by 16,777,216, making the correct key value over 16
million times harder to guess. The jump to 128-bit keys permits even more
keys-so many, that the same hardware that cracked a 56-bit cipher in 5
months would take approximately 1,971,693,055,818,000,000,000 years
to crack a 128-bit code! 

The URL for the above is:

And the URL of a nice story on the distributed.net effort (with some other
interesting ideas for distrubited processing) is:

(forgive me, or don't, if this has already been discussed ad nauseum!)

Robert Brooks / robertb at geocities.com
http://www.geocities.com/SoHo/4535/graph.html (Wallpaper Heaven!)
http://www.flash.net/~totoro/ (Totoro Consulting / totoro at flash.net)
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