Role-Based Access Control (RBAC) is one of the most used models in designing and implementation of security policies, in large networking systems. Basic RBAC model does not consider temporal aspects which are so important in such policies. Temporal RBAC (TRBAC) is proposed to deal with these temporal aspects. Despite the elegance of these models, designing a security policy remains a challenge. Designers must ensure the consistency and the correctness of the policy. The use of formal methods provides techniques for proving that the designed policy is consistent. In this paper, we present a formal modelling/analysis approach of TRBAC policies. This approach uses Hierarchical Timed Coloured Petri Nets (HTCPN) formalism to model the TRBAC policy, and the CPN-tool to analyse the generated models. The timed aspect, in HTCPN, facilitates the consideration of temporal constraints introduced in TRBAC. The hierarchical aspect of HTCPN makes the model “manageable”, in spite of the complexity of TRBAC policy specification. The analysis phase allows the verification of many important properties about the TRBAC security policy.

中文翻译：

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在TRBAC安全策略的正式研究中使用分层定时有色Petri网

基于角色的访问控制（RBAC）是大型网络系统中设计和实现安全策略时最常用的模型之一。基本的RBAC模型未考虑在此类政策中如此重要的时间方面。提出了时间RBAC（TRBAC）来处理这些时间方面。尽管这些模型很优雅，但是设计安全策略仍然是一个挑战。设计人员必须确保策略的一致性和正确性。形式方法的使用提供了证明所设计的策略是一致的技术。在本文中，我们提出了TRBAC政策的正式建模/分析方法。该方法使用分层定时有色Petri网（HTCPN）形式主义对TRBAC策略建模，并使用CPN工具分析生成的模型。在HTCPN中，计时方面 有助于考虑TRBAC中引入的时间限制。尽管TRBAC策略规范很复杂，但HTCPN的层次结构使模型“可管理”。分析阶段允许验证有关TRBAC安全策略的许多重要属性。