Improving the Security of Controlled Quantum Secure Direct Communication by Using Four Particle Cluster States Against an Attack with Fake Entangled Particles

Abstract

A controlled quantum secure direct communication protocol (Zhang et al. Int. J. Theor. Phys. 48:2971-2976) by using four particle cluster states was proposed recently. The aim of Zhang et al. was that the successful realization of communication between Alice and Bob needed the cooperation of a controller, Charlie. However, we show that the controller Charlie's role could be excluded unknowingly. Using fake entangled particles and Bell measurement, the dishonest Bob who generates the initial signals can elicit Alice's secret message without the permission of Charlie. A possible improvement of the protocol is proposed.Keywords Controlled secure direct communication · Cluster state · Fake entangled particles Based on fundamental principles of quantum mechanics, quantum cryptography [1] can obtain unconditional security. Since the first quantum key distribution (QKD) protocol was proposed by Bennett and Brassard [2], quantum cryptography has attracted a great deal of attention. QKD permits the communicators share a secure random key. Different from QKD, quantum secure direct communication (QSDC) [3] and deterministic secure quantum communication (DSQC) [4] are another branch of quantum cryptography, which allow the

Controlled Secure Direct Communication Protocol via the Three-qubit Partially Entangled Set of States

“…Using this attack, the control function of Charlie in the ZZZ protocol can be eliminated by the receiver Bob without the knowledge of Charlie. Moreover, this new attack is also valid for the improved scheme [Yang, Chai, Teng et al (2011)]. But to our disappointment, Qin did not give a further improvement.…”

“…In fact, Bob wants to remove Charlie's control and obtain Alice's secret freely. Yang et al [Yang, Chai, Teng et al (2011)] presented a fake entangled particles attack on the ZZZ protocol, in which Bob prepares two Bell states rather than a four-qubit cluster state. Then, Bob can obtain Alice's secret information freely without Charlie's control.…”

“…Case1: The fake entangled particles attack. In our new proposed CQSDC protocol, it is Charlie rather than Bob who prepares the four particle cluster state, so it is impossible for Bob to prepare two Bell states in Yang et al's protocol [Yang, Chai, Teng et al (2011)] to deliver fake entangled particles attack on Charlie. That is to say, Bob cannot prepare fake entangled particles to deceive Charlie with the attempt of getting rid of control of Charlie.…”

“…Since the Bennett and Brassard's original article [Bennett and Brassard (1984)] was published, quantum key distribution (QKD) has an approach using quantum mechanics [Jiang, Jiang and Ling (2014)] principles for the participants of communication to share a private key with unconditional security. With the development of quantum cryptography [Wei, Chen, Niu et al (2015)] and network communication, security of communication is widely concerned [Chen, Tang, Xu et al (2018); Chen, Sun, Xu et al (2017); ; Xu, Chen, Dou protocol [Yang, Chai, Teng et al (2011)]. However, Qin did not propose a further improved protocol.…”

Quantum oblivious transfer with relaxed constraints on the receiver

“…If it is secure against the participant attack, then it is also secure against the outside eavesdropping from Eve. Later studies showed that lots of quantum cryptographic protocols could not resist participant attacks [19][20][21][22][23][24][25][26][27].…”