In this work, we propose a coherent model for universal composability, called the IITM model (``Inexhaustible Interactive Turing Machine''). A main feature of the model is that it is stated without a priori fixing irrelevant details, such as a specific way of addressing of machines by session and party identifiers, a specific modeling of corruption, or a specific protocol hierarchy. In addition, we employ a very general notion of runtime. All reasonable protocols and ideal functionalities should be expressible based on this notion in a direct and natural way, and without tweaks, such as (artificial) padding of messages or (artificially) adding extra messages.
Not least because of these features, the model is simple and expressive. Also the general results that we prove, such as composition theorems, hold independently of how such details are fixed for concrete applications.
Being inspired by other models for universal composability, in particular the UC model and because of the flexibility and expressivity of the IITM model, conceptually, results formulated in these models directly carry over to the IITM model.
Category / Keywords: foundations / cryptographic protocols, universal composability, modular security analysis Date: received 18 Jan 2013, last revised 21 Dec 2018 Contact author: ralf kuesters at sec uni-stuttgart de Available format(s): PDF | BibTeX Citation Note: Compared to the previous version, we added a discussion on Canetti's UC model, version July 2013. We provided more examples of how the IITM model can be used. The actual model did not change at all. Version: 20181221:103045 (All versions of this report) Short URL: ia.cr/2013/025