| 摘要: |
| 在分布式环境下,利用信任管理机制来实现存取控制已得到人们的一致认同.但是,许可证的存储策略一直是这个领域中一个尚未完全解决的重要问题,而且它直接影响到许可证链的查找等问题.提出了利用许可证的发布者和主体两维信息,采用分布哈希表和Hilbert曲线对许可证进行分布定位的新的许可证存储策略.这种存储策略不仅具有很好的负载平衡的特性,而且为许可证的查找提供了充分的灵活性.同时,利用Hilbert曲线生成时的递归特性及其所具有的局部保持性,实现了在分布式环境中基于部分关键字的许可证查找.在此基础上,提出一种许可证链查找算法,实现了在查询过程中构造最小的许可证图,从而大幅度减少网络中的信息传输量. |
| 关键词: 信任管理 许可证 许可证链 分布哈希表 |
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| 基金项目:Supported by the National Natural Science Foundation of China under Grant Nos.60473069, 604963205 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant No.2005AA4Z3010 (国家高技术研究发展计划(863)) |
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| Certificates Storage Strategy and Search Algorithm Based on Hilbert Curve |
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GAO Ying,CHENG Tao-Yuan,WANG Shan
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| Abstract: |
| It is effective to use trust-management (TM) systems addressing authorization in decentralized environments. However, how to store certificates is an important and unresolved problem in this research area, which determines certificate chain discovery algorithm. In this paper, a new strategy to store certificates is put forward by using two-dimensional certificate information and Hilbert space filling curve. This strategy has not only the characteristic of load balance but also enough flexibility to search for certificates. An optimized certificates search algorithm is put forward, based on the query consisting of partial keyword. In addition to this, an algorithm to discover certificate chain is brought forward for creating the minimum certificates graph reducing the network traffic greatly. |
| Key words: trust-management certificate certificate chain DHT (distributed hash table) |
