Patent Number: 6,298,137

Title: Ring-based public key cryptosystem method

Abstract: A method of communicating information between users of a communications system includes the following steps: generating a ring R, ideals P and Q in R, a set of coset representatives C.sub.Q for the ring R modulo the ideal Q, and a set of coset representatives C.sub.p for the ring R modulo the ideal P; generating at least one public key element h.sub.1, . . . , h.sub.k in the ring R as a function of at least two private key elements .function..sub.1, . . . .function..sub.n in R and the ideal Q of the first user; and transmitting from a first user to a second user a description of the ring R, the ideal Q, the ideal P, and the elements h.sub.1, . . . , h.sub.k in R; generating an element e in R as a function of the ideals P and Q, the public key elements h.sub.1, . . . , h.sub.k, a private message element m in R, and at least one private random element .o slashed..sub.1, . . . , .o slashed..sub.l of the second user; and transmitting the element e from the second user to the first user, such that the first user can determine the message element m by computing a result A in R of evaluating a function F of e, .function..sub.1, . . . , .function..sub.n, computing a coset representative a of A in the set of coset representatives C.sub.q, computing a result B of evaluating a function G of a, .function..sub.1, . . . , .function..sub.n, computing a coset representative b of B in the set of coset representatives C.sub.p, and computing a result c in the set of coset representatives C.sub.p of evaluating a function H of b, .function..sub.1, . . . , .function..sub.n.

Inventors: Hoffstein; Jeffrey (Pawtucket, RI), Pipher; Jill (Pawtucket, RI), Silverman; Joseph H. (Needham, MA)

Assignee: NTRU Cryptosystems, Inc.

International Classification: H04L 9/28 (20060101); H04L 9/30 (20060101); H04L 009/30 (); H04L 009/28 (); H04L 009/08 ()

Expiration Date: 10/02/2018