P2P文件共享系统中的一种基于商品市场模型的访问控制机制

摘要

As Peer-to-peer (P2P) file sharing is increasingly becoming popular as a new paradigm for file exchange> its security has been an issue of concern, and access control is one of the key technologies of system security. However, the decentralized and dynamic characteristic of P2P system makes the traditional access control methods cannot be applied directly, and the existing access control methods for P2P file-sharing system cannot be a good solution to against the large concurrent file-downloading request or bombarded malicious file-downloading requests. To address the above problems, a kind of access control mechanism based on commodity market (ACMCM) in P2P file sharing system is presented in this paper. The market mechanism makes the file-downloading requests in a balanced distribution among the file providers; the price of downloaded file increases in exponential with the number of repeat downloading on same file, so the malicious file downloading is effectively denied; the bandwidth is allocated rationally among the concurrent downloading, and it makes system time used for file-downloading be short as possible. We believe that ACMCM preserves P2P decentralized structure and dynamic property. Finally, the distributed protocol of the major processes is presented.%随着P2P文件共享系统日益成为流行的文件交换方式,其安全问题势必引起关注,而访问控制是P2P系统安全的关键技术之一.由于P2P系统具有分散性和动态性,传统的访问控制机制不能够直接应用于P2P文件共享系统中.而现有针对P2P文件共享系统的访问控制机制不能很好地解决大量并发文件下载请求或者爆发式的恶意文件下载对节点带来的侵害.针对上述问题,文中提出一种基于商品市场模型的访问控制机制(ACMCM),利用市场调节机制使得文件下载请求均衡地分布在多个文件提供者之间；下载文件的价格随着重复下载次数的增加而呈指数增长,有效遏制了恶意下载行为；通过在并发下载之间合理地分配下载带宽,使得并发文件下载占用的系统时间尽量缩短.ACMCM保留了P2P系统的分散性和动态性.最后给出了ACMCM的分布式协议的主要过程的流程.