Patent ID: 8151333
Filing Date: 2012-04-03
Classification: H04L

Abstract:
1. A distributed single sign-on system comprising a plurality of n authentication servers associated with a service provider operable to provide a service to a user, wherein a secret key K S associated with the service provider is split into n distinct secret key shares, each distinct secret key share K S i associated with authentication server A i of the plurality of n authentication servers where 1<i≦n, and wherein each distinct secret key share K S i is sent to its associated authentication server A i along with a service provider identifier SID, and wherein each authentication server A i stores the distinct secret key share K S i in association with the service provider identifier SID, and wherein the splitting of the secret key K S is based on a random polynomial f(x) of order t−1, where 1<t≦n, the random polynomial f(x) having random coefficients and a constant wherein the constant is set to K S , and where any t secret key shares of the secret key K S can be used to reconstruct the secret key K S , and wherein the random polynomial f(x)=K S +a 1 x+ . . . +a t−1 x t-1 mod q where the random coefficients {a i ∈ Z q }, and where q is a large prime number that divides the Euler totient function of a large prime p, and where Z q represents integers from 0 to q−1, and where K S i =f(x i ) for a set of n distinctive values {x i ∈ Z q {0}}.