Is this just more snakeoil or is this real? <<<<<<<< FORWARDED MESSAGE >>>>>>>> From: Ross Anderson <Ross.Anderson@cl.cam.ac.uk> Date: Fri, 20 Sep 1996 09:05:28 +0100 Subject: Seminar in Cryptology and Computer Security *** *** *** *** *** University of Cambridge Computer Laboratory EXTRA SEMINAR SPEAKER: Matt Blaze AT&T Research DATE: Monday 23rd September 1996 at 11.30 am PLACE: Room TP4, Computer Laboratory TITLE: SYMMETRIC-KEY CIPHERS BASED ON HARD PROBLEMS A useful principle in cipher design is to reduce or at least relate closely the cryptanalysis of the cipher to some long-studied problem that is believed to be difficult. Most public-key ciphers follow this principle fairly closely (e.g., RSA is at least similar to factoring). Modern symmetric-key ciphers, on the other hand, can rarely be reduced in this way and so are frequently designed specifically to resist the various known cryptanalytic attacks. In this informal talk, we examine a simple cipher primitive, based on Feistel networks, for which recovery of its internal state given its inputs and outputs is NP-complete. We outline simple and efficient block- and stream- cipher constructions based on this primitive. * * * The regular Michaelmas term seminar series will resume on the 8th October with a series of talks on Tuesday afternoons at 4.15 PM in room TP4, Computer Laboratory, Pembroke Street, Cambridge. A list of speakers will be circulated shortly. * * *