darrylo@hpsrli.HP.COM (Darryl Okahata) (04/19/88)
In comp.mail.elm, dave@csd4.milw.wisc.edu (David A Rasmussen) writes: > A user who uses Elm at my site writes me: [ ... ] > When prompted, the decryption key is: debug [ ... ] > A two-line encoded->decoded message will follow: > [encode] > }K^jy$x3ziAUKBae,|TsodZAaEz_Cnc3#69:?'5$F3myPV > }K^jy$x3ziAUKBae,|TsodZAaEz_Cnc3#69:?'5$F3myPV > [clear] > The encoded->decode message ends just prior to this line. > > The second line should be identical to the first line... But it always > comes out completely garbled Who says that the second line should be identical to the first line??? The second line would decrypt identically to the first line only if a simple substitution cipher is used (or by some amazing -- and very rare -- coincidence). Elm does not use a simple substitution cipher because everyone, their grandmother, and their grandmother before them could break such a cipher in a few minutes (well, maybe a bit longer :-). Elm uses a more sophisticated encryption system that is much more complex, although only slightly more secure. The encryption system used in Elm would probably keep ~90%+ (this is a guess) of the people from reading your encrypted mail. However, many governments (U.S. included, naturally) and many people knowledgeable in cryptology could easily break the system, given enough encrypted text (a few Kbytes). [ ... ] > Dave Rasmussen c/o Computing Services Division @ U of WI - Milwaukee > Internet: dave@csd4.milw.wisc.edu Uucp: uwvax!uwmcsd1!uwmcsd4!dave {o,o} > Csnet: dave%uwmcsd4@uwm Bellnet: +1 (414) 229-5133 \u/ > ICBM: 43 4 58 N/ 87 55 52 W Usnail: 3200 N Cramer #E380, Milw WI 53211 -- Darryl Okahata {hplabs!hpccc!, hpfcla!} hpsrla!darrylo CompuServe: 75206,3074 Disclaimer: the above is the author's personal opinion and is not the opinion or policy of his employer or of the little green men that have been following him all day.