System and method for key distribution using quantum cryptography
AssigneeBritish Telecommunications public limited company
InventorPaul David Townsend
Life of this patent
Estimating the term…
Abstract
A method of communication uses quantum cryptography to encode and decode a signal. A key is distributed on a quantum channel, and information subsequent communicated between the transmitter and receiver on a public channel to determine whether the key has been intercepted. A common transmission medium is used for the quantum channel and public channel. A calibration signal is transmitted over the public channel on the common transmission medium to calibrate the system for the subsequent transmisison of a key on the quantum channel. The trasmission medium may be an optical fibre and the transmitter may switch between a single-photon output and a multiple-photon output to provide quantum channel and public channel respectively.
Claims18
A method of communication using quantum cryptography comprising:
- transmitting a quantum channel and a public channel over a common transmission medium, and
- transmitting a calibration signal over the public channel to calibrate the system for the transmission of a key on the quantum channel.
A method of communication using quantum cryptography comprising:
- transmitting a quantum channel and a public channel over a common transmission medium, and
- transmitting a clock signal over the public channel from a transmitter to a receiver to provide timing information for the subsequent decoding of a key transmitted on the quantum channel.
A communication system for use in a method of quantum cryptography comprising:
- a transmitter,
- one or more receivers
- a network linking the transmitter to the or each receiver,
- the transmitter being arranged to transmit a quantum channel and a public channel on a common transmission medium provided by the network, and
- the transmitter including means for generating a calibration signal for transmission over the common transmission medium.
A communication system for use in a method of quantum cryptography comprising:
- a transmitter,
- one or more receivers,
- a network linking the transmitter to the or each receiver,
- the transmitter being arranged to transmit a quantum channel and a public channel on a common transmission medium provided by the network, and
- the transmitter including a clock that outputs a clock signal on the public channel to provide timing information for subsequent decoding of a key transmitted on the quantum channel.
Dependencies are inferred from the claim text.