Abstract: Mobile Ad Hoc is a special network，its self-organized characteristic makes it face serious security problems.Based on Elliptic curve cryptosystem，a key management scheme for Ad Hoc is proposed.In this scheme we make use of combined public key and fully distributed secret sharing，so it doesn’t need a trusted centre and public key certificates，high extensibility，and it can resist interior and exterior attackers effectively.Analysis show that the security of this scheme is based on the difficulty of solving the elliptic curve cryptography discrete logarithm problem，and its implementation is efficient.

Key words: combined public key, secret sharing, elliptic curve cryptography, Ad Hoc

摘要： 移动Ad Hoc网络是一种特殊的网络，其自组特性决定它将面临严重的安全问题。基于椭圆曲线密码体制，提出了一种适合于Ad Hoc网络的密钥管理方案，该方案利用了组合公钥和完全分布式秘密共享，无需可信中心的参与和公钥证书，可扩展性强，能够有效地抵御网内和网外的攻击者。分析表明，方案的安全性是基于椭圆曲线离散对数问题的难解性，其执行效率较高。

关键词: 组合公钥, 秘密共享, 椭圆曲线密码, Ad Hoc