关键词: 女巫攻击, 页级, 信任系统

Abstract: PageRank，as the most important reputation ranking factor of Google，is prone to Sybil attack as recently research results prove.A higher ranking may offer an economic benefit.Based on some prevenient efforts on finding the best Sybil strategy to manipulate PageRank on its simplest version，the paper focuses on how to use strategy to optimize PageRank into its aimed ranking.Pay attention that the optimization work is done simulative without consideration for complex network environment，so it would still be far away to put such strategy into actual implementation，which is also the future work.

Key words: Sybil, PageRank, reputation system