| 摘要 |
PROBLEM TO BE SOLVED: To provide an encryption system for encryption and decryption using an invariant of a group, and can encrypt and decrypt without sharing a candidate of a plain text between two entities. SOLUTION: The encryption system performs encryption communication between a first and a second entities which share a mathematical space X to which a group G and a group G1 act, and the invariant INV1,..., INVn in the mathematical space X regarding to the group G1. The second entity creates an element x of the mathematical space X so that a plain text Z satisfies Z=(INV1(x),..., INVn(x)) for the invariant, and transmits z=a*g1*x obtained by making a result that an element g1 of the group G1 and a common key "a" of an element of the group G act to the element x. The first entity creates v=a<SP>-1</SP>*z by making inverse element of the common key "a" on the received encryption sentence z, inserts v in the invariant, and makes the value (INV1(v),..., INVn(v)) as the plain text Z. COPYRIGHT: (C)2006,JPO&NCIPI
|
