Patent ID: 6061789
Filing Date: 2000-05-09
Classification: G06F,G06Q,H04L

Abstract:
A method for anonymous, provable information exchange between a sender and an addressee in a computer network, the computer network providinga public key infrastructure, preferably with certification, andan anonymous communication channel available between network users, said method comprising the following steps:said sender C composes an offer request REQ with a subject or merchandise description MD and a digital signature SIG-c of C,REQ=(MD,SIG-c),said REQ is transmitted via said anonymous communication channel to at least one addressee M,said addressee M composes a reply REP with an offer description OD and its digital signature SIG-m, said digital signature SIG-m being computed over a selection of quantities comprising at least one of MD, OD, SIG-c,REP=(OD, SIG-m),and further including M's public key PK-m or public key certificate Cert-m,said sender C, upon receiving said reply REP, uses M's public key PK-m, known, transmitted, or extracted from said public key certificate Cert-m, to encrypt said received SIG-m, thus determining a first temporary value TMP-1,TMP-1=PK-m(SIG-m),said sender C computes a concatenation of said selection of quantities on which said signature SIG-m is based, thus determining a second temporary value TMP-2TMP-2=H(SIG-c/MD/OD),said sender C compares said temporary values TMP-1 and TMP-2, a match indicating genuineness of said offer.