Paper 2000/067 Original: eprint.iacr.org/2000/067 ↗

Universally Composable Security: A New Paradigm for Cryptographic Protocols

Abstract

We present a general framework for representing cryptographic protocols and analyzing their security. The framework allows specifying the security requirements of practically any cryptographic task in a unified and systematic way. Furthermore, in this framework the security of protocols is maintained under a general composition operation, called universal composition. The proposed framework with its security-preserving composition property allow for modular design and analysis of complex cryptographic protocols from relatively simple building blocks. Moreover, within this framework, protocols are guaranteed to maintain their security within any context, even in the presence of an unbounded number of arbitrary protocol instances that run concurrently in an adversarially controlled manner. This is a useful guarantee, that allows arguing about the security of cryptographic protocols in complex and unpredictable environments such as modern communication networks.