Decoherence-full subsystems and the cryptographic power of a private shared reference frame

Journal Article · Wed Sep 01 04:00:00 EDT 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.70.032307· OSTI ID:20646012

Bartlett, Stephen D ^[1]; Rudolph, Terry ^[2]; Spekkens, Robert W ^[3]

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1. School of Physical Sciences, The University of Queensland, Queensland 4072 (Australia)
2. Optics Section, Blackett Laboratory, Imperial College London, London, SW7 2BZ (United Kingdom)
3. Perimeter Institute for Theoretical Physics, 35 King St. N, Waterloo, Ontario N2J 2W9 (Canada)

We show that private shared reference frames can be used to perform private quantum and private classical communication over a public quantum channel. Such frames constitute a type of private shared correlation, distinct from private classical keys or shared entanglement, useful for cryptography. We present optimally efficient schemes for private quantum and classical communication given a finite number of qubits transmitted over an insecure channel and given a private shared Cartesian frame and/or a private shared reference ordering of the qubits. We show that in this context, it is useful to introduce the concept of a decoherence-full subsystem, wherein every state is mapped to the completely mixed state under the action of the decoherence.

• OSTI ID: 20646012
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 70; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CORRELATIONS
DATA TRANSMISSION
ENERGY LEVELS
INFORMATION THEORY
MIXED STATE
QUANTUM MECHANICS
SECRECY PROTECTION