Principles of Commitment Protocols

North Carolina State University, Raleigh NC

Investigators

Abstract

Autonomous parties - both companies and people - who exist in networked environments must perforce interact. Protocols structure and streamline those interactions. Traditional representations of protocols specify legal sequences of actions but not their content. Thus, traditional representations cannot adequately support flexible interactions (e.g., to handle exceptions and exploit opportunities.) This project will develop a richer model of protocols via an inference mechanism, called commitment machines, in which a declarative content is formulated for protocol states and actions in terms of the participants' commitments. Because of its representation of content and its inferencing-based operational rules, a commitment machine effectively encodes a flexible version of a protocol, thereby allowing a wider variety of legal moves than traditional representations. This project seeks to study protocols and commitment machines, capturing the kinds of reasoning needed in practical protocols, such as for e-commerce. Specifically, this project will 1) formulate a semantics for protocols that applies in open, networked applications, 2) represent protocols as generalized commitment machines, 3) implement commitment machines in a tool for protocol analysis and design, 4) evaluate the approach by applying the tool on popular and emerging e-commerce protocols, and 5) classify useful and pathological kinds of commitment machines.