Semi-quantum protocol is a hot topic in quantum cryptography. One of the original motivational reasons to study semi-quantum protocol is to better understand “how quantum” a protocol needs to be in order to gain an advantage over its classical counterpart. Semi-quantum secure direct communication (SQSDC) is an important branch of the semi-quantum protocol, which makes it possible to directly transfer large amounts of data between quantum participant and classical participant without need to share the secret key in advance. In this paper, we propose two new SQSDC protocols based on single photons to study how to reduce the quantum resource requirements of both quantum participant and classical participant. In both protocols, the classical participant requires neither quantum memory or quantum delay lines. We first propose in the first protocol that the quantum participant only need to prepare single-state qubits in the preparation phase, which is different from previous SQSDC protocols. Then we propose in the second protocol that quantum participant can accomplish the same work as the first one even without quantum memory. Efficiency analysis shows that the first protocol is more efficient than some protocol, and the second one can save more quantum resources at the expense of some efficiency. Compared with the existing SQSDC protocols based on single photons, both protocols can use fewer quantum states or quantum resource requirements than other protocols. Finally, we analyze the security of both protocols.
Semi-quantum protocol is a hot topic in quantum cryptography. One of the original motivational reasons to study semi-quantum protocol is to better understand “how quantum” a protocol needs to be in order to gain an advantage over its classical counterpart. Semi-quantum secure direct communication (SQSDC) is an important branch of the semi-quantum protocol, which makes it possible to directly transfer large amounts of data between quantum participant and classical participant without need to share the secret key in advance. In this paper, we propose two new SQSDC protocols based on single photons to study how to reduce the quantum resource requirements of both quantum participant and classical participant. In both protocols, the classical participant requires neither quantum memory or quantum delay lines. We first propose in the first protocol that the quantum participant only need to prepare single-state qubits in the preparation phase, which is different from previous SQSDC protocols. Then we propose in the second protocol that quantum participant can accomplish the same work as the first one even without quantum memory. Efficiency analysis shows that the first protocol is more efficient than some protocol, and the second one can save more quantum resources at the expense of some efficiency. Compared with the existing SQSDC protocols based on single photons, both protocols can use fewer quantum states or quantum resource requirements than other protocols. Finally, we analyze the security of both protocols.
Abstract Based on semi-quantum cryptography and utilizing W-state, this paper introduces two semi-quantum secure direct communication (SQSDC) protocols. SQSDC1 establishes a secret two-way communication channel between a quantum participant and two classical participants. SQSDC2 achieves efficient one-way communication from a quantum user to classical users. Security analysis demonstrates the asymptotic security of the protocols, effectively resisting intercept-measure-resend attacks and entangle-measure attacks from potential eavesdroppers. The efficiency analysis indicates high communication efficiency, with SQSDC1 achieving communication efficiencies of 20%, while SQSDC2 achieves a communication efficiency of 33.33%.
Quantum secure direct communication allows one participant to transmit secret messages to another directly without generating a shared secret key first. In most of the existing schemes, quantum secure direct communication can be achieved only when the two participants have full quantum ability. In this paper, we propose two semi-quantum secure direct communication protocols to allow restricted semi-quantum or “classical” users to participate in quantum communication. A semi-quantum user is restricted to measure, prepare, reorder and reflect quantum qubits only in the classical basis [Formula: see text]. Both protocols rely on quantum Alice to randomly prepare Bell states, perform Bell basis measurements and publish the initial Bell states, but the semi-quantum Bob only needs to measure the qubits in classical basis to obtain secret information without quantum memory. Security and qubit efficiency analysis have been given in this paper. The analysis results show that the two protocols can avoid some eavesdropping attacks and their qubit efficiency is higher than some current related quantum or semi-quantum protocols.
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.
Semi-quantum dialogue (SQD) enables secure bidirectional communication even when one participant has limited quantum capabilities. In order to solve the problems of low efficiency and quantum resource constraints, an efficient SQD protocol using single-photon is proposed. In the SQD, one communicating party needs to have semi-quantum capabilities to complete the dialogue, which could consume lower quantum resource. Moreover, single photons as quantum channels significantly reduces both preparation and operational costs. Finally, decryption can be performed without any classical disclosure, effectively preventing potential information leakage. Security analysis demonstrates resilience against common attacks, including intercept-resend, measure-resend, entanglement-measurement, and Trojan horse attacks, with no information leakage. Compared with existing semi-quantum dialogue protocols, our proposed protocol consumes fewer quantum resources while achieving higher communication efficiency and enhanced security.
Quantum secure direct communication (QSDC) is an important branch of quantum communication that is capable of directly transmitting secret messages over a quantum channel. It may be viewed as a concrete realization of Wyner's wiretap channel theory, which ensures the reliable and secure communication of information in the presence of noise and eavesdropping. Hence it is a fully-fledged quantum-communications protocol, which does not require a separate secret key negotiation phase. By contrast, its quantum key distribution (QKD) counterpart represents a secret key-negotiation protocol, which has to be followed up by a separate classical communication session. The essential difference between these two modes of quantum communication lies in the employment of a block-based data transmission technique, proposed by Long and Liu in 2000. However, the original block-based data transmission requires quantum memory, which is not widely available at the time of writing. Recently, this difficulty has been overcome by using classical coding theory, which has been successfully applied to the single-qubit DL04 QSDC. Here we will present a single-photon-memory QSDC protocol based on entangled pairs of photons. We commence by comparing QSDC to QKD, followed by an example of the single-photon QSDC and single-photon QKD protocol. Then we continue by modifying the so-called two-step QSDC protocol designed for deterministic QKD by reducing the number of qubits in a block into a single one, in which Alice prepares Einstein-Podolsky-Rosen (EPR) photon pairs and partitions them into two parts: the so-called pioneer qubit and the follow-up qubit. The pioneer photon is transferred first to Bob, while the follow-up photon is used either for performing encoding or for eavesdropping detection. Bob extracts the candidate key by combining the two particles of the EPR pair to perform Bell-basis measurement. Then the protocol is transformed into a single-photon-memory QSDC using coding theory. Our theoretical analysis shows that the resultant protocol is robust to individual attacks. Additionally, a high communication efficiency is achieved.
Quantum secure direct communication (QSDC) can transmit secret messages directly from one user to another without first establishing a shared secret key, which is different from quantum key distribution. In this paper, we propose a novel quantum secure direct communication protocol based on signal photons and Bell states. Before the execution of the proposed protocol, two participants Alice and Bob exchange their corresponding identity IDA and IDB through quantum key distribution and keep them secret, respectively. Then the message sender, Alice, encodes each secret message bit into two single photons (| 01〉or|10〉) or a Bell state , and composes an ordered secret message sequence. To insure the security of communication, Alice also prepares the decoy photons and inserts them into secret message sequence on the basis of the values of IDA and IDB. By the secret identity IDA and IDB, both sides of the communication can check eavesdropping and identify each other. The proposed protocol not only completes secure direct communication, but also realizes the mutual authentication. The security analysis of the proposed protocol is presented in the paper. The analysis results show that this protocol is secure against some common attacks, and no secret message leaks even if the messages are broken. Compared with the two-way QSDC protocols, the presented protocol is a one-way quantum communication protocol which has the immunity to Trojan horse attack. Furthermore, our proposed protocol can be realized without quantum memory.