International Association
for Cryptologic Research

We show a black box barrier against constructing public key quantum money from obfuscation for evasive functions. As current post-quantum obfuscators based on standard assumptions are all evasive, this shows a fundamental barrier to achieving public key quantum money from standard tools. Our impossibility applies to black box schemes where (1) obfuscation queries made by the mint are classical, and (2) the verifier only makes (possibly quantum) evaluation queries, but no obfuscation queries. This class seems to capture any natural method of using obfuscation to build quantum money.