Abstract
Communicating Sequential Processes (CSP) is a process algebra, designed for modeling and analyzing the behavior of concurrent systems. Several security protocols are modeled with CSP and verified using model-checking or theorem proving techniques successfully. Unlike other authentication protocols modeled using CSP, each of the Efficient Multi-chained Stream Signature (EMSS) protocol messages are linked to the previous messages, forming hash chains, which introduces difficulties for modeling and verification. In this paper, we model the EMSS stream authentication protocol using CSP and verify its authentication properties with model checking, by building an infinite state model of the protocol which is reduced into a finite state model.