International Business Machines Corporation

Sap Ag

Refik Molva

Laurent Y Gomez

Philippe A Janson

Frederic Montagut

Elsie A Van Herreweghen

Alessandro Sorniotti

Gene Y Tsudik

Konrad Wrona

Annett Laube

Ralf Ch Hauser

Performing an untraceable secret matching between a first credential associated with a first property of a first user and a second credential associated with a second property of a second user includes receiving the first credential, receiving a matching reference formed so the first user can detect a matching of the first property with a remote property from a credential of another user, supplying a first nonce value to the second user, receiving a hidden version of the second credential from the second user formed by the second user on the basis of the second credential, the first nonce value supplied by the first user and a random value locally generated on a side of the second user, and performing the matching by combining the first credential and the received hidden credential with the first nonce value and comparing the combination with the matching reference.

Method and system for performing an untraceable secret matching

A robust and secure password (or key) change method between a user and an authentication server in a distributed communication network is disclosed. The protocol requires the exchange of only two messages between the user desiring the key change and the server, the user's request including, at least partly encrypted, an identification of the sending user, old and new keys, and two nonces, at least one including a time indication. The authentication server's response includes a possibly encrypted accept/reject indication and the regularly encrypted request from the user.

Method and system for changing an authorization password or key in a

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Valbonne, France

Refik Molva