A Symmetric Replication Scheme for Increased Security and Performance in Structured Overlay Networks

Ghodsi, Ali and Alima, Luc Onana and Haridi, Seif (2004) A Symmetric Replication Scheme for Increased Security and Performance in Structured Overlay Networks. [SICS Report]



Existing structured peer-to-peer systems heavily rely on replication as a means to provide fault-tolerance. Many systems use the so-called successor- list scheme for replication. We argue that this scheme has grave limitations. First, these systems are vulnerable to, what we call, Mendacity attacks, where a malicious peer can lie about other peers to gain full control over all replicas of an item. Second, the successor-list scheme prevents the peers from doing concurrent-requests to replicas of an item. We present, and provide full algorithmic specification for, a generic replication scheme called symmetric replication. The scheme is applicable to all existing structured peer-to-peer systems. In contrast to the successor-list scheme, our scheme makes replicas independent of each other, preventing Mendacity attacks while enabling concurrent requests. Concurrent requests can be used for increasing the security by using voting or consensus algorithms to ensure the correctness of replicas. Moreover, concurrent requests can be used for load-balancing of requests, and to add locality awareness. Finally, to maintain the replication factor, the successor-list scheme uses a complex algorithm that involves all peers replicating a departing peer. In contrast, our symmetric replication scheme only involves two peers to restore the replication factor and thus avoids such complex algorithms.

Item Type:SICS Report
Uncontrolled Keywords:Replication, Security, Distributed Hash Tables, Distributed Algorithms, K-ary Trees, DKS, Peer-to-Peer
ID Code:2350
Deposited By:Vicki Carleson
Deposited On:29 Oct 2007
Last Modified:18 Nov 2009 16:06

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