关键词: 信任, 信任安全, 信任攻击, 信任关系网络, 信任关系盗用

Abstract: According to the characteristics that object and subject vulnerabilities exist greatly in trust environment system, the vulnerability utilizing rules and trust relation embezzling rules are used to describe the state transition process of trust relations, the Trust Attack Model（TAM） is proposed. In the model a trust attacker uses object vulnerabilities to escalate trust levels, uses subject vulnerabilities to transit trust relations, and uses synthetically object and subject vulnerabilities to spread and pervade trust relations, therefore a longer attack reachable distance can be reached. Furthermore, a trust relation transitive closure generation algorithm of TAM whose time complexity is polynomial time is proposed, the algorithm can give all trust attack paths based on present vulnerabilities. Through an experiment based on modeling real vulnerabilities for a system, the results show that the model can make a comprehensive analysis to trust security and produce some detailed information such as trust attack graph, trust attack paths and so on. This model has good describing ability to characteristics of trust attack and shows interaction processes among attackers and trust entities. In addition, it can help an administrator to predict possible trust attacks, and then take the corresponding safety measures.

Key words: trust, trust security, trust attack, trust relation network, trust relation embezzling