Qipeng Liu: Hidden Cosets and Applications to Unclonable Cryptography

Friday, October 29, 2021 - 1:00pm to 2:30pm
email dlehto@mit.edu for Zoom Link, 32-370 for hybrid
Qipeng Liu
In 2012, Aaronson and Christiano introduced the idea of subspace states to build public-key quantum money [STOC '12]. Since then, this idea has been applied to realize several other cryptographic primitives which enjoy some form of unclonability.

In this work, we study a generalization of subspace states called coset states. We show that many unclonable cryptographic applications exist in the plain model, assuming indistinguishability obfuscation and one-way functions. These applications include quantum signature tokens, unclonable decryption keys, and copy-protection of PRFs. They were previously not known or only known to exist relative to classical oracles.

Joint work with Andrea Coladangelo, Jiahui Liu, and Mark Zhandry.