关键词: 多重代理签名, 签密, 椭圆曲线, 共享解密

Abstract: Aiming at the problem that many proxy signature schemes can’t provide confidentiality，a new multi-proxy signcryption scheme with shared unsigncryption is proposed in this paper，which is based on the elliptic curve cryptology.The new scheme has the following advanced properties：（1）It provides authentication and confidentiality.（2）The proxy signcrypters and receivers can respectively generate their group keys by themselves with the knowledge proof protocol of double discrete logarithm based on elliptic curve，so it doesn’t need CA to distribute for them.（3）In the scheme，any t or more of n proxy signcrypters can signcrypt a message and any t-1 or fewer proxy signcrypters can’t signcrypt a message，any l or more of m receivers can unsigncrypt the message and any l-1 or fewer receivers can not unsigncrypt the message.（4）The system doesn’t need a security channel and the cost of the system can be lowed.

Key words: multi-proxy signature, signcryption, the elliptic curve, shared unsigncryption