中文摘要：

当将数字签名应用到广播认证时,网络很容易受到DoS（Denial of Service）攻击,比如攻击者不停地广播虚假数据包从而消耗网络的通信资源和计算资源。针对这种情况,提出一种基于弱认证和信誉等级的协议来防御此类DoS攻击。该协议针对分簇的无线传感器网络模型,利用中国剩余定理和单向函数来完成弱认证,同时还引入信誉管理机制来对节点的信誉进行分级。仿真实验表明,与P.Ning和R.Wang等提出的方案相比,本协议在安全性、有效性和防御广播认证中的DoS攻击能力等方面,均具有较好的优势。

英文摘要：

When digital signatures are applied in the broadcast authentication,the related networks are vulnerable to the DoS（Denial of Service）attacks.For example,attackers can keep broadcasting bogus messages,which may induce the exhaustion of both the communication and computation resources.In this paper,based on both a week authentication and a reputation grade,a new scheme is proposed to defend against such DoS attacks.For the cluster-based wireless sensor networks,our scheme uses the Chinese Remainder Theorem（CRT）and one-way function to execute the week authentication.In the meantime,we apply a reputation management to grade the nodes.Our stimulation experiments show that,compared with the schemes of P.Ning and R.Wang,our scheme expressed better advantages on the security,the effectiveness and the ability of defending the DoS attacks against the broadcast authentication.