



01375nas a2200145   4500008004100000245008100041210006900122260001400191520090600205100001901111700002101130700001601151700002501167856003701192       2020                        eng d00aImpossibility of Quantum Virtual Black-Box Obfuscation of Classical Circuits0 aImpossibility of Quantum Virtual BlackBox Obfuscation of Classic  c5/13/20203 a<p>Virtual black-box obfuscation is a strong cryptographic primitive: it encrypts a circuit while maintaining its full input/output functionality. A remarkable result by Barak et al. (Crypto 2001) shows that a general obfuscator that obfuscates classical circuits into classical circuits cannot exist. A promising direction that circumvents this impossibility result is to obfuscate classical circuits into quantum states, which would potentially be better capable of hiding information about the obfuscated circuit. We show that, under the assumption that learning-with-errors (LWE) is hard for quantum computers, this quantum variant of virtual black-box obfuscation of classical circuits is generally impossible. On the way, we show that under the presence of dependent classical auxiliary input, even the small class of classical point functions cannot be quantum virtual black-box obfuscated.</p>1 aAlagic, Gorjan1 aBrakerski, Zvika1 aDulek, Yfke1 aSchaffner, Christian  uhttps://arxiv.org/abs/2005.06432