QRate, MIET and Tomsk State University: A way to measure post-pulses

The main articles are:

• Cryptography
• Quantum cryptography (encryption)

2022: Methodology for determining the probability of post-pulses

A team of researchers from a company developing electronic devices based on quantum technologies QRate, the Moscow Institute of Electronic Technology and Tomsk State University have proposed a way to measure post-pulses. This was announced by QRate on August 25, 2022. Post-pulse is a noise parameter, the measurement accuracy of which is critical for the effective operation of the single photon detector, one of the main elements in quantum cryptography installations.

Illustration: securenews.ru

Quantum cryptography is a method of protecting communications that guarantees the impossibility of hacking them at the level of the laws of quantum physics. The encryption key is distributed using separate quantum particles - photons. In order to extract information from photons, the recipient of the message measures its characteristics using a special device - a single photon detector. The particle transmits energy to the detector and is destroyed, so any attempt to intercept information leads to errors in measurements and becomes visible.

The single photon detector is the only tool for measuring the characteristics of this particle. However, due to technical errors and internal noise, they are not always accurate. The algorithm created by Russian experts reduces the uncertainty of measuring one of the main noise parameters of the detector and thereby increases the reliability of the measured parameters in general.

During the experiment, experts considered six main approaches to measuring post-pulses and identified their key drawback: for example, with an increase in the number of photons in the pulse entering the single photon detector, the number of post-pulses also increases, and the measurements at the output cease to be correct. Then the researchers built another mathematical model and proposed a method for determining the probability of post-pulses, which made it possible to identify the true value of the parameter from experimental data.

world In only a few laboratories specialize in the study of single photon detectors. The largest are in Japan,,,. China Great Britain All of USA them use classic established methods of measuring post-pulses, which have certain disadvantages. This method makes it possible to increase the accuracy of measurements of noise parameters, which is necessary for further combating errors. I am sure that the discovery will be useful to both to scientific the community and industrial partners, noted Anton Losev, head of the experimental group and head of the QRate single photon detector development department.