Search Results (9)

Current private comparison schemes primarily focus on comparing single secret integers using quantum technologies, while the area of private array content comparison remains relatively unexplored. To bridge this gap, we introduce a quantum private array content comparison (QPACC) scheme based on multi-qubit swap test. This scheme integrates rotation operation, quantum homomorphic encryption (QHE), and multi-qubit swap test to facilitate the equality comparison of array contents while ensuring their confidentiality. In our approach, participants encode their array elements into the phases of quantum states using rotation operations, which are then encrypted via QHE. These encrypted quantum states are sent to a semi-honest third party (TP) who decrypts the encoded quantum states and computes the modulus squared sum of the inner products of these decoded quantum states using the multi-qubit swap test, thereby determining the equality relationship of the array contents. To verify the feasibility of the proposed scheme, we conduct a case simulation using IBM Qiskit. Security analysis indicates that the proposed scheme is resistant to quantum attacks (including intercept-resend, entangle-measure, and quantum Trojan horse attacks) from outsider eavesdroppers and attempts by curious participants. Full article

This paper presents a semi-quantum secret sharing (SQSS) protocol based on three-particle W states, designed for efficient and secure secret sharing in quantum-resource-constrained scenarios. In the protocol, a fully quantum-capable sender encodes binary secrets using W, while receivers with limited quantum capabilities reconstruct the secret through collaborative Z basis measurements and classical communication, ensuring no single participant can obtain the complete information independently. The protocol employs a four-state decoy photon technique ($\left\{\right|0⟩,|1⟩,|+⟩,|-⟩\}$) and position randomization, combined with photon number splitting (PNS) and wavelength filtering (WF) technologies, to resist intercept–resend, entanglement–measurement, and double controlled-NOT(CNOT) attacks. Theoretical analysis shows that the detection probability of intercept–resend attacks increases exponentially with the number of decoy photons (approaching 1). For entanglement–measurement attacks, any illegal operation by an attacker introduces detectable quantum state disturbances. Double CNOT attacks are rendered ineffective by the untraceability of particle positions and mixed-basis strategies. Leveraging the robust entanglement of W states, the protocol proves that the mutual information between secret bits and single-participant measurement results is strictly zero, ensuring lossless reconstruction only through authorized collaboration. Full article

As Internet of Things (IoT) technology continues to advance, there is a growing awareness of IoT security within the industry. Quantum communication technology can potentially significantly improve the communication security of IoT devices. Based on semi-quantum cryptography and utilizing single photons, this paper introduces two semi-quantum secure direct communication (SQSDC) protocols for use in smart door locks. Protocol 1 is more efficient, and the efficiency analysis shows that the communication efficiency is as high as 28.57%. Security analysis demonstrates the asymptotic security of the protocols, effectively resisting intercept–measure–resend attacks and entangle–measure attacks from potential eavesdroppers. The extended SQSDC protocol (protocol 2) builds upon protocol 1 by enabling a single qubit to transmit two bits of information, resulting in a double efficiency outcome. Full article

Quantum secret sharing (QSS) is an important branch of quantum cryptography. Identity authentication is a significant means to achieve information protection, which can effectively confirm the identity information of both communication parties. Due to the importance of information security, more and more communications require identity authentication. We propose a d-level $(t,n)$ threshold QSS scheme in which both sides of the communication use mutually unbiased bases for mutual identity authentication. In the secret recovery phase, the sharing of secrets that only the participant holds will not be disclosed or transmitted. Therefore, external eavesdroppers will not get any information about secrets at this phase. This protocol is more secure, effective, and practical. Security analysis shows that this scheme can effectively resist intercept–resend attacks, entangle–measure attacks, collusion attacks, and forgery attacks. Full article

Quantum summation is one of the various applications in secure multi-party computation. However, most of the existing quantum summation protocols assume that the participants possess all the quantum devices. Considering future applications, the capability of the participants must be adjusted before it can be put into practical use. Although Boyer et al. proposed that the semi-quantum environment could be used to solve this problem; another practical problem is the interference by noise. In 2022, Ye et al. proposed a two-party semi-quantum summation (SQS) protocol resistant to the interference of collective noise, in which two classical participants can accomplish the summation of their private binary sequences with the assistance of a quantum semi-honest third party. They proved that their SQS protocol is resistant to various eavesdropping attacks. This paper unveils two risks of information leakage in Ye et al.’s SQS protocol. If the aforementioned security issues are not resolved, Ye et al.’s SQS protocol may not be able to perform private quantum computations securely. Fortunately, the SQS protocol against the collective-dephasing noise proposed in this study is free from the issue of information leakage as well as resistant to various quantum attacks. In addition, the quantum efficiency of the SQS protocol proposed in this study is four times higher than that of Ye et al.’s SQS protocol, which can effectively improve the quantum utilization rate. Full article

In 2019, Zhou et al. proposed semi-quantum identification (also known as semi-quantum authentication, SQA), which proceeds under a measure-resend and measurement-free environment. However, Zhou et al.’s SQA protocol suffers from severe information leakages. An eavesdropper can obtain an intact authentication key without being detected under this environment. In particular, Zhou et al.’s measure-resend SQA protocol is vulnerable to double CNOT attacks, while the measurement-free SQA protocol is vulnerable to man-in-the-middle attacks. Hence, this study reveals the severe security issues of Zhou et al.’s SQA protocol and proposes an improved protocol with guaranteed security. The proposed measure-resend SQA protocol is immune to double CNOT attacks. Since the photons sent back and forth are identical, Eve cannot obtain any information by cross-comparing these photons. In the proposed measurement-free SQA protocol, the eavesdropper cannot obtain the order of the transmitted photons because it was previously a pre-shared key to decide the order of the photons. Hence, the proposed measurement-free SQA protocol can withstand man-in-the-middle attacks. Full article

In this paper, we propose an efficient multi-party quantum secret sharing scheme based on GHZ entangled state. The participants in this scheme are divided into two groups, and share secrets as a group. There is no need to exchange any measurement information between the two groups, reducing the security problems caused by the communication process. Each participant holds one particle from each GHZ state; it can be found that the particles of each GHZ state are related after measuring them, and the eavesdropping detection can detect external attacks based on this characteristic. Furthermore, since the participants within the two groups encode the measured particles, they can recover the same secrets. Security analysis shows that the protocol can resist the intercept-and-resend attack and entanglement measurement attack, and the simulation results show that the probability of an external attacker being detected is proportional to the amount of information he can obtain. Compared with the existing protocols, this proposed protocol is more secure, has less quantum resources and is more practical. Full article

In 2021, Chang et al. proposed an authenticated semi-quantum key-distribution (ASQKD) protocol using single photons and an authenticated channel. However, an eavesdropper can launch a reflective attack to forge the receiver’s identity without being detected. In addition, Chang et al.’s ASQKD protocol assumes an authenticated classical channel between the sender and the receiver. It is considered illogical to have an authenticated channel in the ASQKD protocol. If these security issues are not addressed, the ASQKD protocol will fail to deliver the secret key. Therefore, this study proposes an efficient and secure ASQKD protocol to circumvent these problems using only single photons. Security analysis proves that the proposed ASQKD protocol can effectively avoid reflecting attacks, collective attacks, and other typical attacks. Compared with the existing ASQKD protocols, this study has the following advantages: based on a single photon, it demands less advanced quantum devices, the communication efficiency is higher than most protocols, it reduces the length of the required pre-shared keys, endures reflecting attacks, collective attacks, and there is no need for the classical channel. Full article

To guarantee information security in communication, quantum identity authentication plays a key role in politics, economy, finance, daily life and other fields. In this paper, a new quantum multiparty simultaneous identity authentication protocol with Greenberger–Home–Zeilinger (GHZ) state is presented. In this protocol, the authenticator and the certified parties are the participants with quantum ability, whereas the third party is a classical participant. Here, the third-party is honest and the other two parties may be dishonest. With the help of a classical third-party, a quantum authenticator and the multiple certified parties can implement two-way identity authentication at the same time. It reduces the quantum burden of participants and lowers down the trustworthiness, which makes the protocol be feasible in practice. Through further security analysis, the protocol can effectively prevent an illegal dishonest participant from obtaining a legitimate identity. It shows that the protocol is against impersonation attack, intercept-measure-resend attack and entangle-measure attack, etc. In all, the paper provides positive efforts for the subsequent security identity authentication in quantum network. Full article