Cryptology ePrint Archive: Report 2018/904

Quantum security proofs using semi-classical oracles

Andris Ambainis and Mike Hamburg and Dominique Unruh

Abstract: We present an improved version of the one-way to hiding (O2H) Theorem by Unruh, J ACM 2015. Our new O2H Theorem gives higher flexibility (arbitrary joint distributions of oracles and inputs, multiple reprogrammed points) as well as tighter bounds (removing square-root factors, taking parallelism into account). The improved O2H Theorem makes use of a new variant of quantum oracles, semi-classical oracles, where queries are partially measured. The new O2H Theorem allows us to get better security bounds in several public-key encryption schemes.

Category / Keywords: foundations / post-quantum cryptography, quantum random oracle model, one-way to hiding, public-key encryption, provable security

Date: received 24 Sep 2018, last revised 18 Feb 2019

Contact author: unruh at ut ee, mike@shiftleft org, andris ambainis@lu lv

Available format(s): PDF | BibTeX Citation

Note: Changes: - Extended introduction - Discussion how bounds obtained in existing work change - Proof of Targhi-Unruh transform with the new O2H Theorem

Version: 20190218:140908 (All versions of this report)

Short URL: ia.cr/2018/904