When formalizing security protocols, different specification
languages support very different reasoning methodologies, whose results
are not directly or easily comparable. Therefore, establishing clear mappings
among different frameworks is highly desirable, as it permits various
methodologies to cooperate by interpreting theoretical and practical
results of one system into another. In this paper, we examine the relationship
between two general verification frameworks: multiset rewriting
(MSR) and a process algebra (PA) inspired to CCS and the -calculus.
Although defining a simple and general bijection between MSR and PA
appears difficult, we show that the sublanguages needed to specify cryptographic
protocols admit an effective translation that is not only tracepreserving,
but also induces a correspondence relation between the two
languages. In particular, the correspondence sketched in this paper permits
transferring several important trace-based properties such as secrecy
and many forms of authentication.