| 摘要 |
PURPOSE: A signcryption scheme is provided to operate a signcryption of data with reduced data overhead after a signcryption by forming a conditional access system including a head-end system and at least one smart card. CONSTITUTION: An uncoded EMM(Entitlement Management Message)(40) comprises a header part(41) and a payload part(42). A payload part of the clear text EMM is encrypted through the changed ECIES(Elliptic Curve Integrated Encryption Scheme) mode. An encrypted EMM(50) comprises the header part, the encrypted payload part(52) and the x-coordinate(51) of a random point. The encrypted EMM passes through a digital signature module. The encrypted EMM is signed with the digital signature module to digital. A signcrypted EMM(60) comprises the header part, the encrypted payload, the unique x-coordinate of a random point and an unique signature component(61) of signature. |
