Trust-Management Systems and Methods

A method for performing trust management computations, the method including:

• collecting a group of certificates, each certificate including at least one authorization;
• expressing authorizations using a structure that satisfies certain predefined properties;
• expressing each certificate as a function, wherein each function possesses one or more properties sufficient to ensure that a set of authorizations will have a fixpoint;
• computing a fixpoint of the authorizations, or an approximation thereof;
• making a trust management decision using the result of said computing step.

A system for controlling access to electronic content or processing resources, the system comprising:

• means for receiving a request from a requesting principal to access a piece of electronic content or a processing resource;
• means for collecting a set of one or more certificates relating to the request, the requesting principal, or the electronic content or processing resource;
• means for identifying a root principal from whom authorization is needed in order to grant the request;
• means for performing at least a portion of a least fixpoint computation over said certificates to determine whether the root principal has authorized access to the piece of electronic content or processing resource by the requesting principal;
• and
• means for granting access to the electronic content or processing resource if the least fixpoint computation indicates that the root principal has authorized said access.