## Cryptology ePrint Archive: Report 2005/019

The Full Abstraction of the UC Framework

Jesús F. Almansa

Abstract: We prove that security in the Universal Composability framework (UC) is equivalent to security in the probabilistic polynomial time calculus ppc. Security is defined under active and adaptive adversaries with synchronous and authenticated communication. In detail, we define an encoding from machines in UC to processes in ppc and show it is fully abstract with respect to UC-security and ppc-security, i.e., we show a protocol is UC-secure iff its encoding is ppc-secure. However, we restrict security in ppc to be quantified not over all possible contexts, but over those induced by UC-environments under encoding. This result is not overly-simplifying security in ppc, since the threat and communication models we assume are meaningful in both practice and theory.

Category / Keywords: foundations / foundations, formal cryptographic analysis

Publication Info: Also as BRICS Technical Report RS-04-15. Supersedes extended abstract at DIMACS Workshop, June 2004.

Contact author: jfa at brics dk

Available format(s): PDF | BibTeX Citation

Note: (DIMACS Title: A Notation for Multiparty Protocols of ITM's: Digging from the Tunnel's Other End)

Short URL: ia.cr/2005/019

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