Cryptology ePrint Archive: Report 2004/139

New Notions of Security: Achieving Universal Composability without Trusted Setup

Manoj Prabhakaran and Amit Sahai

Abstract: We propose a modification to the framework of Universally Composable (UC) security [Canetti'01]. Our new notion, involves comparing the protocol executions with an ideal execution involving ideal functionalities (just as in UC-security), but allowing the environment and adversary access to some super-polynomial computational power. We argue the meaningfulness of the new notion, which in particular subsumes many of the traditional notions of security.

We generalize the Universal Composition theorem of [Canetti'01] to the new setting. Then under new computational assumptions, we realize secure multi-party computation (for static adversaries) without a common reference string or any other set-up assumptions, in the new framework. This is known to be impossible under the UC framework.

Category / Keywords: foundations / Environmental Security, Multi-party computation

Publication Info: STOC 2004

Date: received 11 Jun 2004

Contact author: mp at princeton edu

Available formats: Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Version: 20040616:112846 (All versions of this report)

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