Continuous random measurement matrix-based continuous variable quantum key distribution method

Abstract

The invention provides a continuous random measurement matrix-based continuous variable quantum key distribution method. The method comprises the following steps of first, Gaussian modulation of a coherent state by a sending end, wherein the sending end prepares true random numbers of Gaussian distribution and prepares the coherent state, and encodes the coherent state through strength and a phasemodulator according to an element of a Gaussian random number set; second, transmission of a Gaussian signal, wherein the sending end transmits the encoded coherent state signal to a receiving end through a quantum channel; third, demodulation of a continuous random measurement matrix by the receiving end, wherein the receiving end prepares a plurality of binary variables that are distributed continuously and randomly; and fourth, data consultation and privacy amplification. Through adoption of the method, matrix comparison is prevented so that some original data strings are not discarded, further, the method is easy to realize in the prior art. Due to use of continuously distributed phase angles, requirements on performance of a digital-analog converter and a phase modulator are relatively lowered, so that engineering is easy to realize.

Description

technical field [0001] The invention relates to the technical field of quantum secure communication, in particular to a continuous variable quantum key distribution method based on a continuous random measurement base. Background technique [0002] With the rapid development of computer information technology and communication technology, the requirements for information security are increasing day by day. In recent years, with the improvement of the computing power of classical computers and major breakthroughs in quantum computer research, information security systems that rely on mathematical cryptography will face severe challenges. The emergence of quantum secure communication has opened up new ideas and new methods of cryptography based on physical mechanisms. Its appearance has changed the traditional encryption method based on mathematical methods, and its unconditional security based on physical characteristics has brought it unparalleled Advantage. [0003] Quant...

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Problems solved by technology

[0004] In this protocol, if balanced homodyne detection is used at the receiving end, which quadrature component of the quantum state to measure will be determined according to the angle loaded on the phase modulator, and part of the information bits will be discarded according to this angle; if at the receiving end Using heterodyne detection, the study found that the scheme did not double the key rate as expected, but increased the complexity of the system

In addition, in the actual experimental system, many devices and software control programs will be involved. The imperfections of these devices and software will introduce security holes and pose a threat to the actual security of the system.

For example, the voltage jump range between 0 and π / 2 is very large, so the modulation angle may not be the original expected value

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