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arXiv · 1904.11477

Quantum Lazy Sampling and Game-Playing Proofs for Quantum Indifferentiability

Jan Czajkowski·Christian Majenz·Christian Schaffner·Sebastian Zur
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Abstract

Game-playing proofs constitute a powerful framework for non-quantum cryptographic security arguments, most notably applied in the context of indifferentiability. An essential ingredient in such proofs is lazy sampling of random primitives. We develop a quantum game-playing proof framework by generalizing two recently developed proof techniques. First, we describe how Zhandry's compressed quantum oracles~(Crypto'19) can be used to do quantum lazy sampling of a class of non-uniform function distributions. Second, we observe how Unruh's one-way-to-hiding lemma~(Eurocrypt'14) can also be applied to compressed oracles, providing a quantum counterpart to the fundamental lemma of game-playing. Subsequently, we use our game-playing framework to prove quantum indifferentiability of the sponge construction, assuming a random internal function.

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Jan Czajkowski, Christian Majenz, Christian Schaffner, Sebastian Zur. 2019-04-25. Quantum Lazy Sampling and Game-Playing Proofs for Quantum Indifferentiability. https://arxiv.org/abs/1904.11477

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