Patent ID: 8595506

Claim:
An authentication method of a prover device by a verifier device using cryptographic coupons, wherein a coupon comprises, on one hand, a pseudo-random number r i , where i is an index for labeling the coupon, and, on the other hand, a reduced-coupon x i such that x i =ƒ(r i ), where ƒ is a predetermined one-way function, the method comprising: sending, from the verifier device to the prover device, a challenge consisting of a random value c, sending, from the prover device to the verifier device, a response y calculated by using the pseudo-random number r i , said challenge c, and a secret key s belonging to the prover device, and checking, by the verifier device, the validity of said response y based on the challenge c, the reduced-coupon x i corresponding to said pseudo-random number r i , and a public key V corresponding to said secret key s, wherein the verifier device receives said reduced-coupon x i from a source external to the prover device.