International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 28 April 2015

Serge Fehr, Jonathan Katz, Fang Song, Hong-Sheng Zhou, Vassilis Zikas
ePrint Report ePrint Report
It is known that cryptographic feasibility results can change by moving from the classical to the quantum world. With this in mind, we study the feasibility of realizing functionalities in the framework of universal composability, with respect to both computational and information- theoretic security. With respect to computational security, we show that existing feasibility results carry over unchanged from the classical to the quantum world; a functionality is \"trivial\" (i.e., can be realized without setup) in the quantum world if and only if it is trivial in the classical world. The same holds with regard to functionalities that are complete (i.e., can be used to realize arbitrary other functionalities).

In the information-theoretic setting, the quantum and classical worlds differ. In the quantum world, functionalities in the class we consider are either complete, trivial, or belong to a family of simultaneous-exchange functionalities (e.g., XOR). However, other results in the information- theoretic setting remain roughly unchanged.

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