Secure Multiparty Sessions with Topics

TL;DR

This paper introduces a new type discipline for multiparty session calculi that classifies messages by topics, enabling more flexible communication by allowing independent topics to be handled without restrictions.

Contribution

It proposes a novel topic-based type system that relaxes overly restrictive security requirements in multiparty sessions, permitting independent message sequences.

Findings

Supports unrestricted message sequencing on independent topics

Enhances security models with flexible communication protocols

Maintains security guarantees while increasing expressiveness

Abstract

Multiparty session calculi have been recently equipped with security requirements, in order to guarantee properties such as access control and leak freedom. However, the proposed security requirements seem to be overly restrictive in some cases. In particular, a party is not allowed to communicate any kind of public information after receiving a secret information. This does not seem justified in case the two pieces of information are totally unrelated. The aim of the present paper is to overcome this restriction, by designing a type discipline for a simple multiparty session calculus, which classifies messages according to their topics and allows unrestricted sequencing of messages on independent topics.