本文是一篇关于传感器网络安全的综述，详细地从各个层介绍了它的研究情况。-Wireless sensor networks(WSNs) use small nodes with constrained capabilities to sense,collect,and disseminate information in many types of applications.As sensor networks

become wide-spread,security issues become a central concern,

especially in mission-criticaltasks.In this paper,we identify



the

threats and vulnerabilities to WSNs and summarize the defense

methods based on the networking protocol layer analys is ?rst.Then we give a holistic overview of security issues.These issues are divided into seven categories:cryptography,keymanage-

ment,attack detections and preventions,securer outing,secure

location security,secure data fusion,and other security



issues.

Along the way we analyze thead vantages and disadvantages of

current secure schemes in each category.Inaddition,we also summarize the techniques and methods used in these categories,and point out the open research issues and directions in each

area.