Patent ID: 6038316
Filing Date: 2000-03-14
Classification: G06F,G11B,H04L

Abstract:
A method for operating a digital information processing system that distributes encryption information from an authorization processor to a plurality of user processors, the method comprising processor executed steps of:at the authorization processor:selecting a resilience threshold t, and a number N;selecting a generator g of a multiplicative subgroup R of Z.sub.N.sup.*, wherein Z.sub.N.sup.* is a set of numbers less than and relatively prime to N and R consists of powers of g mod N;selecting random numbers k and b.sub.1, . . . , b.sub.t in the range [2:.vertline.R.vertline.], where .vertline.R.vertline. denotes the size of R and where the random numbers are relatively prime to .vertline.R.vertline.;generating g.sub.j =g.sup.b.sbsp.j mod N for 1.ltoreq.j.ltoreq.t;distributing to the user processors encrypted information with g.sub.j ; andreceiving a value n from a user processor, and returning to the user processor a signet a, wherein:a=k-b.sub.1 n- . . . -b.sub.t n.sup.t mod .vertline.R.vertline.;whereby the signet a is for enabling the user processor to generate a decryption key K to decrypt the encrypted information.