Cryptology ePrint Archive: Report 1998/016
Quantum Computers Render Quantum Key Distribution Unconditionally Secure Over Arbitrarily Long Distances
Hoi-Kwong Lo and H. F. Chau
Abstract: Abstract: Quantum cryptography has long been claimed to be useful for
achieving many tasks that are impossible from the perspective of
conventional cryptography. Arguably, the most important problem
in quantum cryptography has been a rigorous proof of the security of
quantum key distribution, the most well-known application.
This notoriously hard problem has eluded researchers for years and has
become even more important after the recent surprising demonstration
of the insecurity of many other quantum cryptographic schemes including
quantum bit commitment. Here, we solve this long standing problem by
showing that, given quantum computers, quantum key distribution over an
arbitrarily long distance of a realistic noisy channel can be made
unconditionally secure. The novel technique we use is reduction from a
quantum scheme to a classical scheme. The security in realistic noisy
environments is then proven by using the recent theory of fault-tolerant
Category / Keywords: Quantum key distribution, quantum cryptography, key-distribution problems, unconditional security.
Publication Info: Appeared in the THEORY OF CRYPTOGRAPHY LIBRARY and has been included in the ePrint Archive. This paper was removed from the library in January 1999 at the authors' request due to copyright issues.
Date: received May 22, 1998, withdrawn January 1999
Contact author: hkl at hplb hpl hp com
Available formats: (-- withdrawn --)
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