关键词: P2P技术, VPN技术, P2P-VPN, Petri网

Abstract: With the popularity of the P2P technology， the security problem on P2P network has attracted more and more attention. To address the issue， a model called P2P-VPN virtual network framework is proposed， which sets up a virtual network group according to the specific application. The framework is not only to achieve the secure P2P transmission， but also to apply P2P technology to the local area network applications. The completeness of security mechanism of P2P-VPN is proved by Petri Nets and some other formal methods. The simulation results from the prototype system show that although the framework introduces a series of security processing procedure， it will not cause significant decline in data transfer rate.

Key words: peer to peer （P2P）, virtual private network （VPN）, P2P-VPN, Petri Net