As soon as a P2P application grows to the point where it becomes interesting, the issues of trust and security appear on the horizon. The core of the paper is on how to build trustful peer-to-peer networks with TLS and X.509 certificates under JXTA architecture. The use of authentication, authorization, and encryption establishes trust in P2P applications. Without a foundation of trust, many types of interesting applications such as e-commerce won’t take hold on top of the P2P infrastructure. As soon as a P2P application grows to the point where it is interesting, the issues of trust and security appear on the horizon. The core of the paper is on how to build trustful peer-to-peer networks with TLS and X.509 certificates under the JXTA architecture. The use of authentication, authorization, and encryption integrity trust in P2P applications. Without a foundation of trust, many types of interesting applications such as e-commerce will not take hold on top of the P2P infrastructure.