Some information security problems introduce by the newly-emerging P2P technique are analyzed. Despite its promising capability of anti-destruction and privacy protection

P2P has quite a few intrinsic faults

including the lack of mutual trust mechanism

content authentication

etc.

which may expose a P2P net- work to several kinds of attacks

such as route attack

firewall traversing and so on. Accordingly

measures on how to build a solid defense system are present. Finally

we introduce some research directions about the security of P2P technique.