一种不经意的基于数字签名的电子信封

提出了基于Schnorr签名及基于Elgamal签名的不经意的电子信封方案，并且在计算性Diffe—Hellman假设下证明了其安全性．即在计算性Diffe—Hellman假设成立的条件下，不持有可信第三方签名的接收者不能计算出共享密钥，因而不能得到消息，且偷听者不能恢复Diffe—Hellman方案的共享密钥．所提协议仅对原签名做少许改变，不需要第三方参与，具有较高效率．此方案给OSBE提供了一种新的选择，也为OSBE在移动代理的应用提供了可能。

Oblivious signature-based envelope

An oblivious signature-based envelope scheme for Schnorr signature and Elgamal signature wss proposed, and the security of which based on the computational the Diffe-Hellman assumption was proved. That is to say, if the computational Diffie-Hellman assumption is held in our scheme, receivers without the signature of the trusted third party can not obtain the shared key derived from Diffie-Hellman protocol, accordingly they can not decrypt the cipher-text. Eavesdroppers also can not acquire any useful message. The proposed scheme has only a slight adaptation to the original signature and does not require the trusted third party after the setup phase. The scheme is efficient. It provides a new choice for OSBE and the possibility of the usage of OSBE in mobile agent.