Distributed Credential Chain Discovery in Trust Management

Distributed Credential Chain Discovery in Trust Management
复制标题

DOI：
10.3233/jcs-2003-11102
复制
发表时间：
2003-02
期刊：
J. Comput. Secur.
影响因子：
--
通讯作者：
Ninghui Li;W. Winsborough;John C. Mitchell
Ninghui Li;W. Winsborough;John C. Mitchell
中科院分区：
其他
文献类型：
--
作者：
Ninghui Li;W. Winsborough;John C. Mitchell

文献摘要

被引文献

相似文献

我们介绍了一个简单的基于角色的信任管理语言RT 0和一个集合论语义。我们还介绍了证书图作为一个可搜索的表示在RT 0的证书，并证明了可达性的证书图是健全的和完整的RT 0的语义。基于证书图，我们给出了目标导向算法做证书链发现在RT 0中，无论是当证书存储是集中式的，当证书存储是分布式的。目标导向算法从访问控制查询开始，搜索与查询相关的凭据，同时避免考虑与手头的访问控制决策无关的潜在大量凭据。这种方法提供了更好的预期情况下的性能比自底向上的算法。我们展示了如何将我们的算法应用于SDSI 2.0（SPKI/SDSI 2.0的“SDSI”部分）。我们的目标导向的分布式链发现算法根据需要查找和检索凭据。我们证明该算法是正确的，证明该算法是健全的和完整的凭证图组成的凭证检索，该算法检索构成一个可遍历链的所有凭证。我们进一步介绍了一个存储类型系统的RT 0，保证遍历链时，凭证类型良好。这种类型的系统还可以帮助提高搜索效率，引导搜索在正确的方向，使分布式链发现与大量的凭证可行。
We introduce a simple Role-based Trust-management language RT0 and a set-theoretic semantics for it. We also introduce credential graphs as a searchable representation of credentials in RT0 and prove that reachability in credential graphs is sound and complete with respect to the semantics of RT0. Based on credential graphs, we give goal-directed algorithms to do credential chain discovery in RT0, both when credential storage is centralized and when credential storage is distributed. A goal-directed algorithm begins with an access-control query and searches for credentials relevant to the query, while avoiding considering the potentially very large number of credentials that are unrelated to the access-control decision at hand. This approach provides better expected-case performance than bottom-up algorithms. We show how our algorithms can be applied to SDSI 2.0 (the 'SDSI' part of SPKI/SDSI 2.0).Our goal-directed, distributed chain discovery algorithm finds and retrieves credentials as needed. We prove that the algorithm is correct by proving that the algorithm is sound and complete with respect to the credential graph composed of the credentials it retrieves, and that the algorithm retrieves all credentials that constitute a traversable chain. We further introduce a storage type system for RT0, which guarantees traversability of chains when credentials are well typed. This type system can also help improve search efficiency by guiding search in the right direction, making distributed chain discovery with large number of credentials feasible.