In each CA certification area can build hierarchical models or network models,then by traditional bridge trust model can also reach intercommunication among different areas,so that CA and entities can trust each other.

In order to solve the problem of mutual communication of PKI trust system based on the comparison of five trust models commonly used in PKI and with reference to the advantages of these models,especially the bridge CA model,a new model— multilevel bridge certificate authority(MBCA) model,is constructed.

This paper analyzer the often used trust models and proposes a new multi-level zoning bridge trust model which adopts single trust model inside organizations while using mixed trust model among outer trust zones.

An improved DyTrust trust model;

Fuzzy autonomous trust model based on open network;

Research into a trust model based on subjective trust and recommendation;

Research on P2P Trust Models;

PKI Trust Mechanisms and Its Application in Trust Models;

Researches on Trust Models of P2P Network Security;

Then the authors sum up the studies about trust model in e-commerce, and point out the research direction about trust studies in e-commerce in the future.

To evaluate trust values of nodes and establish trust relationship in nodes, a trust model is proposed on the basis of the analyses of the existing trust models and the minimal principle of uncertainty metric.

This article first analyzes the character and weakness of the traditional fire walls,then introduces three new type firewall technologies : Distributed Firewall Technology , Intranet Safety Technology on Intelligent Fire-wall, Firewall Grope Security Protection Architecture based on Trust Mode , and analyzes their structure characters and work methods in detail.