Dense-Coding Attack on Three-Party Quantum Key Distribution Protocols

Abstract

Cryptanalysis is an important branch in the study of cryptography, including both the classical cryptography and the quantum one. In this paper we analyze the security of two three-party quantum key distribution protocols (QKDPs) proposed recently, and point out that they are susceptible to a simple and effective attack, i.e. the dense-coding attack. It is shown that the eavesdropper Eve can totally obtain the session key by sending entangled qubits as the fake signal to Alice and performing collective measurements after Alice's encoding. The attack process is just like a dense-coding communication between Eve and Alice, where a special measurement basis is employed. Furthermore, this attack does not introduce any errors to the transmitted information and consequently will not be discovered by Alice and Bob. The attack strategy is described in detail and a proof for its correctness is given. At last, the root of this insecurity and a possible way to improve these protocols are discussed.Comment: 6 pages, 3 figure

Multi-user quantum key distribution with collective eavesdropping detection over collective-noise channels

“…Thus far, many MQCP-CDs [34,35,[55][56][57] have been attacked since the unitary operations used in those protocols can be discriminated unambiguously (by a single use) if an eavesdropper utilizes some special attack strategies, such as dense-coding attack [35] and fake-signal attack. [55] It is just because there is still no effective method for constructing the required unitary operations that some improper ones were used in those protocols.…”

“…On the other hand, this strategy can also reduce the hardware requirement for the implementation of the protocol, since all the users (except for the center who is responsible for preparing and measuring states) only need to perform certain unitary operations in the whole executing procedure of the protocol. To date, much attention has been focused on the collective detection strategy and a lot of MQCPs have been proposed by utilizing it (for simplicity, we will call the MQCP which uses collective detection MQCP-CD), [34][35][36][37][38][39][40][41] including QKD, [34][35][36] QPC, [37] QSS, [38][39][40] and QSQC. [41] In an MQCP-CD, all the users (except for the center) just need to be capable of performing certain unitary operations.…”

“…Second, none of the participants (all the users and the center) in our protocol needs to be equipped with a quantum storage machine. As storing quantum qubits is still a very difficult task in reality, our protocol is more feasible than the ones [34][35][36] in which the quantum storage machine is required. In addition, our protocol can resist various kinds of attacks from both outside eavesdroppers and a dishonest center.…”

Programmable Quantum Networked Microgrids

“…Further, it has been identified that QKD itself is vulnerable to denial of service (DoS) attacks [16]. Any attempt to learn keys on quantum optical equipment causes noise, potentially leading to the exhaustion of keys.…”

Cryptanalysis of the arbitrated quantum signature protocols

“…As pointed out by Lo and Ko, breaking cryptographic systems was as important as building them [26]. In the study of quantum cryptography, quite a few effective attack strategies have been proposed, such as intercept-resend attacks [27], entanglementswapping attacks [28,29], teleportation attacks [30], densecoding attacks [31][32][33], channel-loss attacks [34,35], denialof-service attacks [36,37], correlation-extractability attacks [38][39][40], Trojan horse attacks [41,42], and participant attacks [29,33]. Understanding those attacks will be helpful for us to design new schemes with high security.…”