Patent ID: 7415614

Claim:
A method for allowing a first computer device to be authenticated by at least one second computer device during a communication session of limited duration between the first computer device and the at least one second computer device, the method comprising: a step, for a user, of logging on said first computer device by executing a log-on software program and by introducing personal identifiers, said personal identifiers enabling the checking of the identity of said user and the accessing of a private signature key of said user; a step, for said log-on software program, of producing: a session identifier data Id, a set of one or more private numbers Q 1 , Q 2 , . . . , Q m and respective public numbers G 1 , G 2 , . . . , G m , each pair of numbers (Q i , G i ) verifying either the equation G i ·Q i v ≡1 mod n or the equation G i ≡Q i v mod n, wherein m is an integer greater than or equal to 1, i is an integer between 1 and m, and wherein v is a public exponent, and wherein n is a public module equal to the product of f private prime factors designated by p 1 , . . . , p f , at least two of these prime factors being different from each other, wherein f is an integer greater than 1, said public module n being small relative to the private signature key and such that said public module n cannot be factorized by a computer having state-of-the-art computing power in a time as short as the duration of said session, and a certificate, by signing with said private signature key at least said session identifier data Id and said public module n; disabling the execution of the log-on software program after the log-on process is completed; the method further comprising, at least during the first connection of said first computer device to each of said at least one second computer devices: a step, for said user, of starting execution of a proof software program acting as a witness in a zero-knowledge authentication protocol; sending said certificate to the at least one second computer device; a step, for said at least one second computer device, of starting execution of a verification software program acting as a verifier in said zero-knowledge authentication protocol; a step, for said verification software program, of opening said certificate with a public key associated with said private signature key, and of extracting from this certificate the session identifier data Id and the public module n; and a step, for the proof software program and for the verification software program of completing said zero-knowledge authentication protocol.