Cryptology ePrint Archive: Report 2010/212

Quantum Proofs of Knowledge

Dominique Unruh

Abstract: We motivate, define and construct quantum proofs of knowledge, proofs of knowledge secure against quantum adversaries. Our constructions are based on a new quantum rewinding technique that allows us to extract witnesses in many classical proofs of knowledge. We give criteria under which a classical proof of knowledge is a quantum proof of knowledge. Combining our results with Watrous' results on quantum zero-knowledge, we show that there are zero-knowledge quantum proofs of knowledge for all languages in NP (assuming quantum one-way permutations).

Category / Keywords: foundations / Quantum cryptography, proofs of knowledge

Date: received 15 Apr 2010, last revised 14 Apr 2011

Contact author: unruh at mmci uni-saarland de

Available formats: PDF | BibTeX Citation

Note: The proofs in the previous revision contained an error.

(Page 14, line 6 from bottom: "(1-|Phi><Phi|/nu_i^2) is positive" is incorrect.)

The proofs have been rewritten (and simplified).

Version: 20110414:064104 (All versions of this report)

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