University of Trento
Canetti's universal composition theorem and the joint state composition theorems are useful and widely employed tools for the modular design and analysis of cryptographic protocols. However, these theorems assume that parties participating in a protocol session have pre-established a unique Session ID (SID). While the use of such SIDs is a good design principle, existing protocols, in particular real-world security protocols, typically do not use pre-established SIDs, at least not explicitly and not in the particular way stipulated by the theorems. As a result, the composition theorems cannot be applied for analyzing such protocols in a modular and faithful way.