基于門限機制的密鑰管理方案能提供高的安全性，但認證成功率較低，可擴展性差；基于證書鏈的密鑰管理方案適合自組網的特點，但其安全性僅取決于證書鏈中節點的信任度，不能滿足高安全要求的應用環境。該文提出了門限機制和證書鏈信任值方法相結合的混合式密鑰管理和認證方案，在增加少量通信量的情況下，方案提高了自組網的認證成功率和系統的安全性，較好地平衡了自組網的安全性和認證成功率，滿足自組網應用的安全要求。
關 鍵 詞 自組網; 證書鏈; 密鑰管理; 門限機制

A New Hybrid Key Management Scheme for Ad hoc Networks
WANG Hao1，XIE Ying1，ZHENG Wu2
(1. College of Automation, Chongqing University of Posts and Telecommunications Nan′an Chongqing 400065; 2. School of Computer Science and Engineering, University of Electronic Science and Technology of China Chengdu 610054)
Abstract Key management schemes based on threshold mechanism can provide high security, but lower certificate success rate and bad scalability; key management schemes based on certification chain satisfy self-organized features, but their security depends on trust degree of nodes and could not be applied high security environment. We advance hybrid key management scheme based on threshold mechanism and certification chain. Simulation shows that with less increment of communication overhead, our scheme can improve both certificate success rate and system security and better balances security and availability, and satisfies security needs of Ad hoc networks.
Key words Ad hoc; certification chain; key management; threshold mechanism

無線移動自組網是一種節點可任意移動、拓撲結構高度動態變化、沒有預設網絡基礎設施的多跳無線網絡。這種無線網絡具有可臨時組網、快速展開、無控制中心、抗毀滅等特點，在軍事通信和民用系統中有著廣泛的應用。然而，由于自組網的無線鏈路、動態拓撲、缺乏集中管理和資源受限等特點，其本身就是很脆弱的，容易遭受多種攻擊，而且傳統的安全機制不再適合于它，極大地阻礙了自組網的應用，特別是在關系到國防安全的軍事領域。自組網的密鑰管理和認證是自組網安全研究的核心問題之一，也是自組網安全研究中最困難的問題之一，是研究自組網安全通信和安全路由的基礎[1]。