Patent ID: 6115472
Filing Date: 2000-09-05
Classification: H04L

Abstract:
A contents transmission control method for performing authentication processing between user terminal equipment that a user uses on a network and verifier's equipment, said method comprising the steps;(a) wherein, as an initial registration procedure, said user terminal equipment computes, from a user identifier A and a password S held in secrecy, data W.sub.0 for use in the next authentication session, data W.sub.1 for use in the authentication session after the next authentication session and data M.sub.0 for checking the validity of said data W.sub.1 and registers them in said verifier equipment, together with an initial value of the authentication session number n in association with said user identifier A;(b) wherein, letting n be a positive integer, said verifier equipment receives, in an n-th authentication session, a service request and said user identifier A from said user terminal equipment, then reads out the authentication session number n of said user, and sends said number n to said user terminal equipment;(c) wherein said user terminal equipment uses said user identifier A, said authentication session number n sent from said verifier equipment and said password S held in secrecy to compute data V.sub.n-1 to be authenticated in the current authentication session, data W.sub.n+1 for use in the authentication session after the next authentication session and data M.sub.n for checking the validity of said data W.sub.n+1 and sends said computed data to said verifier equipment, together with contents data desired to transmit, if any;(d) wherein said verifier equipment compares data W.sub.n-1 for use in the current authentication session, computed from said user identifier A and said data V.sub.n-1 sent from said user terminal equipment in said step (c) with already registered authenticated data W.sub.n-1, and further compares validity verification data M.sub.n-1 computed from registered data W.sub.n for use in the next authentication session and said data V.sub.n-1 to be authenticated in said current authentication session, with already registered validity verification data M.sub.n-1 ;(e) wherein when said data compared in said step (d) agree, said verifier equipment accepts said user as valid, then transmits and receives information of the service requested by said user, then updates previously registered data W.sub.n-1, W.sub.n and M.sub.n-1 with said data W.sub.n received in the previous authentication session and for use in the next authentication sessions said data W.sub.n+1 for use in the authentication session after the next authentication session and said validity verification data M.sub.n for said data W.sub.n+1 sent from said user terminal equipment in the current authentication session, and said verifier equipment increments said authentication session number n by one; and(f) wherein if said data compared in said step (d) do not agree, said verifier equipment decides said user is invalid and rejects contents transmission thereafter and holds unchanged said data W.sub.n-1, M.sub.n, M.sub.n-1 and n registered in the previous authentication session.