Backflash Attack

The Backflash Attack exploits the phenomenon where Avalanche Photodiodes (APDs) used in QKD systems emit photons—known as backflash photons—during detection events. These photons can leak back into the quantum channel, allowing the threat actor (Eve) to potentially gather critical information about the detection settings without alerting the users of the QKD system. 


Literature

[Arnon2019] S. Arnon. "Quantum technology for optical wireless communication in datacenter security and hacking" In: Proceedings Volume 10945, Broadband Access Communication Technologies XIII; 109450H. (2019) 10.1117/12.2505733.
[Kepferman2018] J. Kepferman and S. Arnon. "Zero-error attacks on a quantum key distribution FSO system" In: OSA Continuum 1, 1079-1086. (2018) 10.1364/OSAC.1.001079.
[Kurtsiefer2001] C. Kurtsiefer, P. Zarda, S. Mayer, and H. Weinfurter. "The breakdown flash of silicon avalanche photodiodes-back door for eavesdropper attacks?" In: Journal of Modern Optics, 48(13), 2039–2047. (2001) 10.1080/09500340108240905.
[Meda2017] A. Meda, I. Degiovanni, A. Tosi, Z. Yuan, G. Brida, and M. Genovese. "Quantifying backflash radiation to prevent zero-error attacks in quantum key distribution" In: Light Sci. Appl. 6, e16261. (2017) 10.1038/lsa.2016.261.
[Meda2018] A. Meda, I. Degiovanni, A. Tosi, Z. Yuan, G. Brida, and M. Genovese. "Quantum key distribution security threat: the backflash light case" In: Proceedings Volume 10674, Quantum Technologies 2018; 1067418. (2018) 10.1117/12.2307704.
[Pinheiro2018] P. Pinheiro, P. Chaiwongkhot, S. Sajeed, R. Horn, J. Bourgoin, T. Jennewein, N. Ltkenhaus, and V. Makarov. "Eavesdropping and countermeasures for backflash side channel in quantum cryptography" In: Opt. Express 26, 21020-21032. (2018) 10.1364/OE.26.021020.
[Shi2017] Y. Shi, J. Lim, H. Poh, P. Tan, P. Tan, A. Ling, and C. Kurtsiefer. "Breakdown fash at telecom wavelengths in InGaAs avalanche photodiodes" In: Opt. Express 25, 30388–30394. (2017) 10.1364/OE.25.030388.

QID: A-0080
Tier: T0
Type: Quantum
Tactic: Execution
Created: 2024-04-12
Updated: 2024-08-12

Technique → Countermeasures

List of countermeasures applicable to this technique.

Items: 2
Description Countermeasure

Employ optical isolation (in the direction from the receiver out) [Meda2017,Meda2018].

Deploy spectral filters [Kurtsiefer2001].