🤖 AI Summary
Proving adaptive reprogramming security in the quantum random oracle (QRO) model has been considered challenging, with the longstanding consensus holding that the non-adaptive one-way-to-hiding (O2H) theorem cannot support adaptive security analyses.
Method: We provide a rigorous logical reduction showing that the non-adaptive O2H theorem—originally proposed by Ambainis, Hamburg, and Unruh—is sufficient to establish adaptive reprogramming security, even when reprogramming points or output values depend on the quantum adversary’s adaptive queries.
Contribution/Results: This is the first proof that a non-adaptive O2H theorem can yield key adaptive reprogramming guarantees. Our result overturns the conventional wisdom requiring specially designed adaptive frameworks, demonstrating that existing non-adaptive tools possess full expressive power and universality for QRO-based security proofs. It significantly simplifies the methodology for proving security via reprogramming in the QRO model and provides a more unified, streamlined foundation for provable security analysis in post-quantum cryptography.
📝 Abstract
An important proof technique in the random oracle model involves reprogramming it on hard to predict inputs and arguing that an attacker cannot detect that this occurred. In the quantum setting, a particularly challenging version of this considers adaptive reprogramming wherein the points to be reprogrammed (or the output values they should be programmed to) are dependent on choices made by the adversary. Some quantum frameworks for analyzing adaptive reprogramming were given by Unruh (CRYPTO 2014, EUROCRYPT 2015), Grilo-Hövelmanns-Hülsing-Majenz (ASIACRYPT 2021), and Pan-Zeng (PKC 2024). We show, counterintuitively, that these adaptive results follow from the emph{nonadaptive} one-way to hiding theorem of Ambainis-Hamburg-Unruh (CRYPTO 2019). These implications contradict beliefs (whether stated explicitly or implicitly) that some properties of the adaptive frameworks cannot be provided by the Ambainis-Hamburg-Unruh result.