Quantum key distribution
AssigneeNokia Technologies Oy
InventorsJoachim Wabnig, Antti Niskanen, Hongwei Li, David Bitauld
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Abstract
Methods and apparatus for distribution of keys are disclosed. An optical signal for carrying encoded information in accordance with a quantum key distribution scheme is generated. The generated optical signal has a wavelength which is changed to another wavelength prior to transmission of the optical signal. The optical signal carrying the encoded information and having the changed wavelength is received, where after decoding of the information takes place by means of detector apparatus operating in the changed wavelength.
Claims15
A method for distributing a quantum encryption key, the method comprising:
- encoding a sequence of random qubit states onto an optical signal having a first wavelength,
- changing the first wavelength of the optical signal to a shorter second wavelength, and thereafter
- transmitting the optical signal having the shorter second wavelength with the encoded sequence of random qubit states in accordance with a faint pulse quantum key distribution scheme comprising on average less than one photon per pulse.
A method for decoding a quantum encryption key, the method comprising:
- receiving an optical signal carrying an encoded sequence of random qubit states in accordance with a faint pulse quantum key distribution scheme comprising on average less than one photon per pulse, wherein the optical signal is received having a second wavelength and the sequence of random qubit states is encoded thereon at a longer first wavelength, and
- decoding the sequence of random qubit states using an optical detector operating in the second wavelength.
An apparatus, comprising:
- an optical encoder configured to encode a sequence of random qubit states onto an optical signal having a first wavelength;
- at least one crystal configured to change the first wavelength of the optical signal received from the optical encoder to a shorter second wavelength prior to transmission of the optical signal from the apparatus;
- and
- an attenuator configured to reduce power of the optical signal received from the at least one crystal for transmission of the optical signal in accordance with a faint pulse quantum key distribution scheme comprising on average less than one photon per pulse.
An apparatus, comprising:
- an optical interface configured to receive an optical signal carrying an encoded sequence of random qubit states in accordance with a faint pulse quantum key distribution scheme comprising on average less than one photon per pulse, wherein the optical signal is received having a second wavelength and the information is encoded thereon at a longer first wavelength, and
- an optical decoder configured to decode the sequence of random qubit states in the second wavelength.
Dependencies are inferred from the claim text.