Binder is a logic-based security language by John DeTreville

We introduce the concept of a security language, used to express security statements in a distributed system. Most existing security languages encode security statements as schematized data structures, such as ACLs and X.509 certificates. In contrast, Binder is an open logic-based security language that encodes security statements as components of communicating distributed logic programs.

Soutei, a dialect of Binder, is a trust-management system by Andrew Pimlott and Oleg Kiselyov. It attempts to improve upon and replace simple data structures like access control lists in order to accommodate large and volatile sets of users and resources, complicated constraints, and distributed administration.

Soutei brings Binder from a research prototype into the real world. Supporting large, truly distributed policies required non-trivial changes to Binder, in particular mode-restriction and goal-directed top-down evaluation. To improve the robustness of our evaluator, we describe a fair and terminating backtracking algorithm.