Comment on “Scheme of the arrangement for attack on the protocol BB84”

Dmitri L. Khokhlov

Jonte R. Hance, JG Rarity

In a recent paper (Scheme of the arrangement for attack on the protocol BB84, Optik 127(18):7083-7087, Sept 2016), a protocol was proposed for using weak measurement to attack BB84. This claimed the four basis states typically used could be perfectly discriminated, and so an interceptor could obtain all information carried. We show this attack fails when considered using standard quantum mechanics, as expected - such ``single-shot' quantum state discrimination is impossible, even using weak measurement.

Ohta Fumio, Hisayoshi SATO, Takaragi Kazuo

Pedro Juan Roig, Salvador Alcaraz, Katja Gilly +2 more

Dmitry Anatolevich Kronberg, S. N. Molotkov

A quantum scheme for an optimal attack on protocol BB84, the most studied protocol of quantum cryptography, is constructed. The physical implementation of this scheme on the basis of linear fiber-optical elements and the two-particle “controlled NOT” quantum transformation is proposed.

Hong-Wei Li, Zhen−Qiang Yin, Shuang Wang +4 more

Unconditional security of the BB84 quantum key distribution protocol has been proved by exploiting the fundamental laws of quantum mechanics, but the practical quantum key distribution system maybe hacked by considering the imperfect state preparation and measurement respectively. Until now, different attacking schemes have been proposed by utilizing imperfect devices, but the general security analysis model against all of the practical attacking schemes has not been proposed. Here, we demonstrate that the general practical attacking schemes can be divided into the Trojan horse attack, strong randomness attack and weak randomness attack respectively. We prove security of BB84 protocol under randomness attacking models, and these results can be applied to guarantee the security of the practical quantum key distribution system.