- A spooky encryption scheme for relations computable by quantum circuits, from the quantum hardness of an LWE-based circular security assumption. This yields the first quantum multi-key fully-homomorphic encryption scheme with classical keys. - Constant-round zero-knowledge secure against multiple parallel quantum verifiers from spooky encryption for relations computable by quantum circuits. To enable this, we develop a new straight-line non-black-box simulation technique against parallel verifiers that does not clone the adversary's state. This forms the heart of our technical contribution and may also be relevant to the classical setting. - A constant-round post-quantum non-malleable commitment scheme, from the mildly super-polynomial quantum hardness of LWE.
Category / Keywords: cryptographic protocols / multi-party computation, post-quantum Date: received 8 Nov 2020 Contact author: bartusek james at gmail com Available format(s): PDF | BibTeX Citation Version: 20201110:125632 (All versions of this report) Short URL: ia.cr/2020/1395