Attacks on Quantum Cryptography

Anindita Banerjee

Dmitry Anatolevich Kronberg

Coherent state quantum cryptography protocols are of interest due to their easy implementation. However, the security proof of such protocols against all attacks can be tricky because of the attenuation in the communication channel that can be exploited by an eavesdropper. In this work, an attack on the subcarrier wave quantum cryptography protocol has been built, which generalizes the photon number splitting attack. The efficiency of the attack has been analyzed, in particular, for the case where the eavesdropper does not have quantum memory.

Leon Groot Bruinderink

Zhaoxu Ji, Huanguo Zhang

Entanglement-measurement attack is one of the most famous attacks against quantum cryptography. In quantum cryptography protocols, eavesdropping checking is an effective means to resist this attack. There are currently two commonly used eavesdropping checking methods: one is to prepare two sets of non-orthogonal single-particle states as decoy states, and determine whether there are eavesdroppers in the quantum channel by comparing the states obtained by measurements with the original states; The other is to prepare two sets of non-orthogonal entangled states and use their entanglement correlations to judge whether there are eavesdroppers in the quantum channel. In this paper, we theoretically demonstrate how quantum cryptography can utilize these two eavesdropping checking methods to resist entanglement-measurement attacks. We take the quantum cryptography protocols based on maximally entangled states as examples to demonstrate the proof process, transitioning from qubit-based protocols to qudit-based ones.

张盛, 王剑, 唐朝京

Counterfactual quantum cryptography,recently proposed by Noh,is featured with no transmission of signal particles.This exhibits evident security advantages,such as its immunity to the well-known photon-number-splitting attack.In this paper,the theoretical security of counterfactual quantum cryptography protocol against the general interceptresend attacks is proved by bounding the information of an eavesdropper Eve more tightly than in Yin’s proposal [Phys.Rev.A 82 042335(2010)].It is also shown that practical counterfactual quantum cryptography implementations may be vulnerable when equipped with imperfect apparatuses,by proving that a negative key rate can be achieved when Eve launches a time-shift attack based on imperfect detector efficiency.

Chao Wang, Haonan Yao, Baonan Wang +3 more