Cryptology ePrint Archive: Report 2018/264

Security proof for Quantum Key Recycling with noise

Daan Leermakers and Boris Skoric

Abstract: Quantum Key Recycling aims to re-use the keys employed in quantum encryption and quantum authentication schemes. We consider QKR protocols where classical information is embedded in qubit states. A partial security analysis for such protocols was done in [LS2018]. In the current paper we introduce a number of small protocol modifications and provide a security proof. Our proof is based on a computation of the statistical distance between the real quantum state of the system and a state in which the keys are completely secure. This is a non-asymptotic result. It also determines how much privacy amplification is needed as a function of the bit error rate. It turns out that less privacy amplification is needed than suggested by the min-entropy analysis in [LS2018].

Category / Keywords: quantum cryptography, quantum key recycling

Date: received 12 Mar 2018, last revised 7 Sep 2018

Contact author: b skoric at tue nl

Available format(s): PDF | BibTeX Citation

Note: Corrected a mistake in the state conditioning.

Version: 20180907:093942 (All versions of this report)

Short URL: ia.cr/2018/264


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