https://doi.org/10.1140/epjd/e2009-00128-3
Random unitary qubit channels: entropy relations, private quantum channels and non-malleability
1
Faculty of Informatics, Masaryk University, Botanická 68a, 602 00 Brno, Czech Republic
2
Institute of Physics, University of Pécs, Ifjúság útja 6, 7624 Pécs, Hungary
3
Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, 1525 Budapest, Hungary
Corresponding author: a koniorm@gmail.com
Received:
12
November
2008
Published online:
17
April
2009
Channels encrypting quantum bits by the application of randomly chosen unitary operators are studied. Quantities based on averages of linear entropies which characterize certain aspects of the encoding quality and the non-malleability of the channels are introduced. The relation between the entropy of the classical key and the choice of the encryption operators with the behaviour of these properties is discussed. The extension of exact private quantum channels in order to improve non-malleability via additional encryption operators is considered.
PACS: 03.67.-a – Quantum information / 03.67.Dd – Quantum cryptography and communication security / 03.67.Hk – Quantum communication
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2009
