[ont.events] ICR Dec 7 Prof Gilles Brassard Minimum Disclosure Proofs of Knowledge

cfry@watdcsu.waterloo.edu (C.Fry - Inst. Computer Research) (11/30/88)

                       Minimum Disclosure Proofs of Knowledge

          by

          Prof. Gilles Brassard

          of

          Universite de Montreal

          Abstract

          Assume I have found a proof of Fermat's last theorem.  How  could
          I convince you of this without disclosing anything about my proof
          beyond its existence and my knowledge of it?  More generally, let
          us  say  that an information is verifiable if its correctness can
          be established efficiently by use of a public  verification  pro-
          cedure.   In order to convince you that I have the verifiable in-
          formation I claim to have, I could simply show it to you and  let
          you run the verification procedure.  This would be a maximum dis-
          closure proof of this knowledge because it results in your learn-
          ing all the information.

          I will  discuss  general  minimum  disclosure  proof  techniques.
          These allow me to convince you beyond any reasonable doubt that I
          have the information I claim, but in a way that does not help you
          determine  this  information.   Using such techniques, I can con-
          vince you, for instance, that I know the factors of a given large
          integer  without helping you factor it, or that I know an isomor-
          phism between two given graphs without helping you determine  any
          such  isomorphism.   This technique extends to the case of proba-
          bilistically verifiable information.

          The talk will be self-contained:  no prior background on cryptog-
          raphy or zero-knowledge is required.

          DATE:       Wednesday, December 7, 1988

          TIME:       3:30 p.m.

          PLACE:      University of Waterloo, Davis Centre, Room 1302

          Everyone is welcome.  Refreshments served.