Re: DES & RC4-48 Challenges
On Mon, 21 Aug 95 23:13:06 -0400 you wrote:
Hello all,
Lets face it the real challenge is DES, but those 56 bits are quite a bit harder than 40. 65536 times harder in fact.
40 bit code a tad and set to work. It sounds as if it is comparable to the RSA-129 prime that was cracked (OK its probably a touch harder but machines are faster now).
So who wants to make an RC-48 and a DES challenge?
Not having my copy of The Differential Cryptanalysis of the Data Encryption Standard handy, I'd like to know about the distributability of this type of DES attack. Done right, we could significantly reduce the time complexity. The main problem, of course, would be coordinating such an effort. I seem to recall this attack requiring lots of known plaintexts. Time to review the text, I suppose.... Does the Federal Reserve still use single-key DES? Dan ****************************************************************************** "I think, therefore I am" - Descartes Dan Bailey "I don't think, therefore I'm a moustache." - Sartre dan@milliways.org Worcester Polytechnic Institute and The Restaurant at the End of the Universe ******************************************************************************
I don't think the differential Cryptanalysis attack helps very much. You need a somewhat improbable quantity of chosen plaintext to attempt it. You would get further with a direct attack I suspect. In any case lets do RC4-48 or RC4-44 first as proof of ability. Another idea, lets crack CMDF, IBMs weakened key DES. After DES the only other crack of interest thats in range is the meet in the middle attack on two key DES. Clipper looks a bit off in the distance still. (We will get it one day, probably not until 2010 though). I think we can probably do DES within two years. Phill
Dan wrote: |Not having my copy of The Differential Cryptanalysis of the Data |Encryption Standard handy, I'd like to know about the distributability |of this type of DES attack. Done right, we could significantly reduce |the time complexity. | The main problem, of course, would be coordinating such an effort. I |seem to recall this attack requiring lots of known plaintexts. Time |to review the text, I suppose.... | Does the Federal Reserve still use single-key DES? The forms of differential cryptanalysis that I'm aware of require The cracker to adaptively atack the encrypting or decrypting device. I therefore do not believe that they are especially applicable to financial transactions schemes, most of which change keys quite frequently. JWS
participants (3)
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dan＠milliways.org -
hallam＠w3.org -
solman＠MIT.EDU