Cryptology ePrint Archive: Report 2014/201

From Input Private to Universally Composable Secure Multiparty Computation Primitives

Dan Bogdanov and Peeter Laud and Sven Laur and Pille Pullonen

Abstract: Secure multiparty computation systems are commonly built form a small set of primitive components. Composability of security notions has a central role in the analysis of such systems, since it allows us to deduce security properties of complex protocols from the properties of its components. We show that the standard notions of universally composable security are overly restrictive in this context and can lead to protocols with sub-optimal performance. As a remedy, we introduce a weaker notion of privacy that is satisfied by simpler protocols and is preserved by composition. After that we fix a passive security model and show how to convert a private protocol into a universally composable protocol. As a result, we obtain modular security proofs without performance penalties.

Category / Keywords: cryptographic protocols / secure multiparty computation, universal composability

Original Publication (in the same form): Proceedings of the 2014 IEEE 27th Computer Security Foundations Symposium

Date: received 17 Mar 2014, last revised 29 May 2014

Contact author: pille pullonen at cyber ee

Available format(s): PDF | BibTeX Citation

Note: Updated the old version with more intuition about the defined concepts.

Version: 20140529:125823 (All versions of this report)

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