Enhancing Path Reliability against Sybil Attack by Improved Multi-Path-Trees in SDN

Single-path routing in Software Defined Network (SDN) is vulnerable to Sybil attacks, which can damage the routing and even the entire network by forging the identification of multiple normal nodes. Meanwhile, the multi-path routing has been proved to be able to improve the routing security in SDN significantly. In this paper, we aim to enhance the path reliability against Sybil attacks. We first present one random and three targeted Sybil attacker locating models which incorporate degree, betweenness, and PageRank information respectively. Secondly, we propose an improved Multi-Path-Trees (iMPT) algorithm which performs a review of Sybil nodes by calculating node reliability and uses a partial re-routing method to avoid incorrect deletion of routing paths on the multi-path tree. Finally, the experimental simulations on two kinds of classical generated networks and a real network confirm the effectiveness of our proposed algorithm for resisting Sybil attacks in SDN.