International Association for Cryptologic Research

International Association
for Cryptologic Research


Paper: Redeeming Reset Indifferentiability and Applications to Post-Quantum Security

Mark Zhandry , Princeton University and NTT Research
DOI: 10.1007/978-3-030-92062-3_18
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Conference: ASIACRYPT 2021
Abstract: Indifferentiability is used to analyze the security of constructions of idealized objects, such as random oracles or ideal ciphers. Reset indifferentiability is a strengthening of plain indifferentiability which is applicable in far more scenarios, but has largely been abandoned due to significant impossibility results and a lack of positive results. Our main results are: - Under \emph{weak} reset indifferentiability, ideal ciphers imply (fixed size) random oracles, and domain shrinkage is possible. We thus show reset indifferentiability is more useful than previously thought. - We lift our analysis to the quantum setting, showing that ideal ciphers imply random oracles under quantum indifferentiability. - Despite Shor's algorithm, we observe that generic groups are still meaningful quantumly, showing that they are quantumly (reset) indifferentiable from ideal ciphers; combined with the above, cryptographic groups yield post-quantum \emph{symmetric} key cryptography. In particular, we obtain a plausible post-quantum random oracle that is a subset-product followed by two modular reductions.
Video from ASIACRYPT 2021
  title={Redeeming Reset Indifferentiability and Applications to Post-Quantum Security},
  author={Mark Zhandry},