Cryptology ePrint Archive: Report 2012/177

Everlasting Quantum Security

Unruh, Dominique

Abstract: A protocol has everlasting security if it is secure against adversaries that are computationally unlimited after the protocol execution. This models the fact that we cannot predict which cryptographic schemes will be broken, say, several decades after the protocol execution. In classical cryptography, everlasting security is difficult to achieve: even using trusted setup like common reference strings or signature cards, many tasks such as secure communication and oblivious transfer cannot be achieved with everlasting security. An analogous result in the quantum setting excludes protocols based on common reference strings, but not protocols using a signature card. We define a variant of the Universal Composability framework, everlasting quantum-UC, and show that in this model, we can implement secure communication and general two-party computation using a signature card as trusted setup.

Category / Keywords: foundations / Quantum cryptography, everlasting security, universal composability

Date: received 3 Apr 2012

Contact author: unruh at ut ee

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Version: 20120411:160647 (All versions of this report)

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