| 摘要 |
PROBLEM TO BE SOLVED: To enhance security against identification attack, while suppressing a traffic in a discretionary elliptic curve cryptography protocol using a discretionary elliptic curve.SOLUTION: An elliptic curve calculation unit 111 of an elliptic curve cryptography apparatus 11 implements an elliptic curve cryptography protocol to acquire a point P on an elliptic curve. When the point P is defined as an input, an element of a subset J is u, and Q=P-f(u), a coding unit 112 outputs a code corresponding to the element u and an inverse image v=f(Q) as a member of a subset I. In this regard, I and J are the subsets of a finite field, I is a section, at least one of I and J is a proper subset of the finite field, and f is a map reflecting an element z of the finite field on a point f(z) on the elliptic curve. A communication unit 113 transmits the code acquired by the coding unit 112 via a network to the elliptic curve cryptography apparatus 12.SELECTED DRAWING: Figure 1 |
