Visible to the public Custard: Computing Norm States over Information StoresConflict Detection Enabled

TitleCustard: Computing Norm States over Information Stores
Publication TypeConference Paper
Year of Publication2016
AuthorsAmit K. Chopra, Munindar P. Singh
Conference NameProceedings of the International Conference on Autonomous Agents and MultiAgent Systems (AAMAS)
Date Published05/2016
Conference LocationSingapore
KeywordsApr'16, Formal Specification and Analysis of Security-Critical Norms and Policies, NCSU

Norms provide a way to model the social architecture of a sociotechnical system (STS) and are thus crucial for understanding how such a system supports secure collaboration between principals,that is, autonomous parties such as humans and organizations. Accordingly, an important challenge is to compute the state of a norm instance at runtime in a sociotechnical system.

Custard addresses this challenge by providing a relational syntax for schemas of important norm types along with their canonical lifecycles and providing a mapping from each schema to queries that compute instances of the schema in different lifecycle stages. In essence, Custard supports a norm-based abstraction layer over underlying information stores such as databases and event logs. Specifically, it supports deadlines; complex events, including those based on aggregation; and norms that reference other norms.

We prove important correctness properties for Custard, including stability (once an event has occurred, it has occurred forever) and safety (a query returns a finite set of tuples). Our compiler generates SQL queries from Custard specifications. Writing out such SQL queries by hand is tedious and error-prone even for simple norms, thus demonstrating Custard's practical benefits.

Citation KeyAAMAS-16:Custard