pdf icon
Volume 8 (2012) Article 21 pp. 461-486
Two-Source Extractors Secure Against Quantum Adversaries
Received: August 17, 2010
Published: September 19, 2012
Download article from ToC site:
[PDF (305K)]    [PS (1241K)]    [PS.GZ (331K)]
[Source ZIP]
Keywords: extractors, quantum information
ACM Classification: F.1.2, F.2.0, F.2.2, F.2.3
AMS Classification: 68Q10, 68Q12, 68Q17, 68Q25

Abstract: [Plain Text Version]

We initiate the study of multi-source extractors in the quantum world. In this setting, our goal is to extract random bits from two independent weak random sources, on which two quantum adversaries store a bounded amount of information. Our main result is a two-source extractor secure against quantum adversaries, with parameters closely matching the classical case and tight in several instances. Moreover, the extractor is secure even if the adversaries share entanglement. The construction is the Chor-Goldreich (1988) two-source inner product extractor and its multi-bit variant by Dodis et al. (RANDOM'04). Previously, research in this area focused on the construction of seeded extractors secure against quantum adversaries; the multi-source setting poses new challenges, among which is the presence of entanglement that could potentially break the independence of the sources.