基于CPK的可证安全组群密钥交换协议

CPK组合公钥密码体制无需证书来保证公钥的真实性，克服了用户私钥完全由密钥管理中心生成的问题。丈中基于CPK设计了一个高效常数轮的组群密钥交挟协议，并且协议在CDH假设下可证安全和具有完美的前向安全性。该协议只需两轮通信即可协商一个组群会话密钥，无论在通信以及计算方面均很高效。此外该协议提供了一个设计组群密钥交换协议的方法，大部分的秘密共享体制均可直接应用于该协议。

Provable CPK-based Group Key Exchange Protocol

Combined public key cryptography（CPK） does not need certificates to guarantee the authenticity of public keys, and thus avoids the problem that user＇ s private key completely depends on the key management center（KMC）. Based on CPK, an efficient constant-round group key exchange protocol is designed, which is provably secure under the intractability of computation Diffie-Hellman problem and achieves perfect forward security. This protocol has only two communication rounds, so it is more efficient than other protocols both in communication and in computation. Moreover, this protocol provides a method for designing efficient constant-round group key exchange protocols, and most secret sharing schemes could be directly applied in constructing this protocol.