In this paper, we present the research of the blinding attack on single photon avalanche diodes (SPAD) based on InGaAs structure which is used in quantum key distribution systems with modulated laser radiation. One of the variants of this attack is using continuous wave (CW) light but there is protection from it like monitoring of SPAD’s current. Thus, we use modulated CW radiations. Modulation allows us to establish parameters of blinding pulses. We studied the dependencies of the detector’s bias current on blinding pulse energy using different widths of light pulses in the range from 4ns to 20 ns than we applied various repetition rates which are 10 MHz, 5 MHz, 2.5 MHz, and 1MHz. Even we investigate this dependence using the not rectangular shape of pulses on repetition rates mentioned above.
For examining QKD systems for sustainability to the “backflash” attack, it is necessary to measure the probability of photon re-emission and calculate the maximum possible probability of backflash for the secret key to remain secure. In this paper, we present research on backflash probabilities dependencies on parameters of fiber-based QKD systems. The SPAD gate width for each QKD system and quantum communication protocol is individual, therefore, it is necessary to consider the dependence of the probability of photon re-emission on the SPAD gate width. Moreover, as a result of Laser Damage Attack, active elements, such as a variable attenuator or a pulsed laser, may not work quite stable, eventually, as far as the mean photon number per pulse (μ) varies within a small range, the maximum backflash probability can fluctuate. We demonstrate an experimental setup of correlation “backflash” measurements by optical reflectometry with very low dark count rate and parasitic noise, furthermore, the contribution of reflected photons is negligible in comparison with the classical optical reflectometry scheme. Therefore, the signal-to-noise ratio was increased by at least two orders of magnitude. The obtained experimental data demonstrate the variation of the backflash probability of the single-photon detector depending on the SPAD gate width and the mean photon number per pulse sent by Alice to Bob. Analysis of the calculated backflash probabilities enables to estimate the maximum possible information leakage, depending on the parameters of equipment. In the future, the obtained experimental results can be used to adjust the optimal parameters of QKD systems to guarantee communication protocol security.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.