
VOLUME 81  ISSUE 7 
PAGE 437

Using of smallscale quantum computers in cryptography with manyqubit entangled states

K. V. Bayandin, G. B. Lesovik
L. D. Landau Institute for Theoretical Physics RAS, 117940, Moscow, Russia

PACS: 03.67.a

Abstract
We propose a new cryptographic protocol. It is suggested to encode information in ordinary binary form into manyqubit entangled states with the help of a quantum computer. A state of qubits (realized, e.g., with photons) is transmitted through a quantum channel to the addressee, who applies a quantum computer tuned to realize the inverse unitary transformation decoding the message. Different ways of eavesdropping are considered and the estimation of the time, needed for determining the secret unitary transformation, is given. It is shown, that using even small quantum computers can serve as a basis for very efficient cryptographic protocols. For a suggested cryptographic protocol the time scale on which communication can be considered secure is exponential in the number of qubits in the entangled states and in the number of gates used to construct the quantum network.


Download PS file (GZipped, 59.7K)

Download PDF file (169K)


