Quantum secure direct communication, as an important branch of quantum communication, possesses strict information-theoretic security and can achieve secure communication in channel environments with noise interference and eavesdropping threats. As voice communication is the most fundamental and widespread communication method in daily life, guaranteeing its security and efficiency has become an important research topic in current communication technology. One-way quantum secure direct communication technology can build an efficient and reliable security barrier for voice communication services, effectively preventing the leakage of private information in voice communication. This paper proposes a duplex voice communication scheme based on one-way quantum secure direct communication. By adopting a method combining multi-task parallel processing and stream processing, the communication rate and transmission delay performance of the system are significantly improved. Relying on quantum secure direct communication technology and the one-time-key encryption channel within the system, duplex voice communication is achieved securely. The real-time temperature drift compensation algorithm is introduced to ensure the long-term stable operation of the system. At the same time, through the real-time temperature drift prediction mechanism, the strategy selection during the call process is optimized to ensure the quality of the voice communication. To verify the feasibility and performance of this scheme, a one-way quantum secure direct communication duplex voice communication system was built in the laboratory environment, and comprehensive performance indicator tests were conducted. The test results show that the constructed one-way quantum secure direct communication system can fully meet the performance requirements of duplex voice communication. The realization of this system successfully achieves the goal of secure and efficient quantum voice communication, laying an important technical foundation for further expanding the practical application scenarios of quantum communication technology and promoting the industrialization development of quantum communication.
Quantum secure direct communication, as an important branch of quantum communication, possesses strict information-theoretic security and can achieve secure communication in channel environments with noise interference and eavesdropping threats. As voice communication is the most fundamental and widespread communication method in daily life, guaranteeing its security and efficiency has become an important research topic in current communication technology. One-way quantum secure direct communication technology can build an efficient and reliable security barrier for voice communication services, effectively preventing the leakage of private information in voice communication. This paper proposes a duplex voice communication scheme based on one-way quantum secure direct communication. By adopting a method combining multi-task parallel processing and stream processing, the communication rate and transmission delay performance of the system are significantly improved. Relying on quantum secure direct communication technology and the one-time-key encryption channel within the system, duplex voice communication is achieved securely. The real-time temperature drift compensation algorithm is introduced to ensure the long-term stable operation of the system. At the same time, through the real-time temperature drift prediction mechanism, the strategy selection during the call process is optimized to ensure the quality of the voice communication. To verify the feasibility and performance of this scheme, a one-way quantum secure direct communication duplex voice communication system was built in the laboratory environment, and comprehensive performance indicator tests were conducted. The test results show that the constructed one-way quantum secure direct communication system can fully meet the performance requirements of duplex voice communication. The realization of this system successfully achieves the goal of secure and efficient quantum voice communication, laying an important technical foundation for further expanding the practical application scenarios of quantum communication technology and promoting the industrialization development of quantum communication.
Abstract Quantum secure direct communication is a quantum communication technology that uses quantum states as carriers to transmit information securely and directly, first proposed by a team at Tsinghua University in 2000. Quantum communication broadly refers to information transfer processing tasks accomplished through the transmission of quantum states, which can be categorized into three types based on the content transmitted: quantum key distribution for transmitting random numbers, quantum secure direct communication for transmitting classical information, and quantum teleportation for transmitting quantum information. After more than two decades of development, quantum secure direct communication has matured and entered practical application: a theoretical framework tailored for scenarios with high loss, high noise, and stringent security requirements has been established; experimental demonstrations of quantum direct communication in optical fibers and free space have been completed; three milestone systems for quantum secure direct communication at the metropolitan, intercity, and network levels have been built; and successful trials have been conducted in various scenarios such as 5G private networks and banking applications. Quantum secure direct communication offers multiple applications: it prevents information leakage by detecting eavesdropping, ensuring information security; identifies exposed locations by monitoring surveillance activities, providing technical support for preventing targeted eliminations and safeguarding commanders' personal safety; and detects intrusion and tampering behaviors, offering novel protection for cybersecurity. Currently, quantum direct communication has been incorporated into relevant planning documents in China, the European Union, and the United States, and is undergoing rapid development. This article briefly outlines the historical development, fundamental principles, research advancements, and future prospects of quantum direct communication.
A significant problem facing cybersecurity is that most client/server identity authentication schemes depend on computational complexity which is recently challenged by the super exponential computational abilities of quantum computers. Quantum cryptography with its quantum mechanics principles solves this problem and provides mathematically un-hackable secure communication for the quantum computers epoch. Biometric authentication has a big challenge related to its protection as it has to be submitted and stored in encrypted form. Unfortunately, most existing biometric cryptosystems rely on classical cryptography, so they are insecure in quantum era. This problem is solved in this paper by introducing a novel three-factor biometric quantum identity authentication scheme combining something you know (password), something you produce (client’s voice), and something you are (client’s face image) is proposed. The scheme consists of two phases: client enrollment and client login/authentication. The methodology is to use in the enrollment phase, two layers of quantum encryption for the client’s voice signal. Each layer consists of two simple quantum circuits of SWAP and C-NOT quantum gates respectively using a different pseudorandom key obtained from a cellular automata (CA) pseudorandom generator. The proposed scheme has many merits. Firstly, it introduces a new design of muti-factors quantum biometric authentication scheme as the biometric voice data is processed, transmitted, and stored at the server database in an encrypted unconditionally secure quantum form which provides parallel processing, real-time communications, inherent level of security against attacks, tamper-proof security and exponential powerful storage capability due to the quantum properties. Secondly, the proposed scheme achieves double-layers security by combing quantum voice encryption and quantum secure direct communication in one process such that the quantum channel eavesdropper cannot obtain any valuable information in case of information leakage. Thirdly, the distribution and management of encryption key problem is solved as there is no need for key exchange prior to communication. Fourthly, it achieves high communication efficiency as although it is a three-factor biometric identity authentication, only one biometric data is sent in quantum encrypted form to the server. Fifthly, the numerical simulations showed that the proposed scheme has large key space, high key sensitivity and more robust performance against different types of attacks compared to other existing classical and quantum voice encryption schemes. Finally, as an identity authentication method, the proposed scheme achieves identification accuracy of 100% with zero False Rejection Rate (FRR) and zero False acceptance rate (FAR) which is perfect.
Quantum communication realizes information-theoretic security using photonic quantum states, for example, quantum secure direct communication (QSDC), which can achieve secure and reliable communication in a channel with both noise and eavesdroppers. However, QSDC suffers from large losses and short communication distances, thus being impractical for applications. Here, we have proposed a one-way quasi-QSDC protocol with single photons. This protocol enables the simultaneous transmission of information and key exchange using the same single photons and is robust against loss and error because it uses error correction and spectrum expansion techniques. In a proof-of-principle demonstration using weak coherent pulses, the system achieved a real-time secure transmission rate of 2.38 kilobits per second over a 104.8-kilometer standard telecommunication fiber, which set world records in both aspects. This system paved the way for the practical application of QSDC and offers a unique method to detect eavesdropping online, which is crucial in certain circumstances.
In the paper, a protocol of quantum secure direct communication (QSDC) based on EPR entangled state and a quantum state of one particle is presented. The proposed protocol of QSDC uses the idea of one time pad of classical cryptology. The concept of data block and the method of split-step transmission are introduced into the proposed protocol of QSDC. According to the property of quantum, the eavesdropper can get nothing from quantum communication system, so the security of whole QSDC system is ensured. A part of secret message which will be transmitted is loaded on entangled states by processing quantum dense encoding operation on entangled particles. A nonorthogonal mixed state of single particle is introduced into the proposed protocol in order to improve the transmission efficiency, hence another part of secret message which will be transmitted is loaded on states of single particle. The private key and secret message are transmitted directly at the same time on quantum channel. So the proposed scheme of QSDC shall gain higher efficiency as well as complexity increase, and the system be proved the security by performance analysis.
By studying the properties of the mixture of Bell state particles and single photons,in the paper we design a quantum code scheme with high coding capacity,and propose a novel quantum secure direct communication protocol with high transmission efficiency.Alice prepares Bell state particles and single photons,and divides Bell state particles into two sequences SA and SB.SB is sent to Bob for the first security check through using quantum correlation properties of particles.When the check result shows that the quantum channel is safe,by using the designed quantum code scheme, Alice encodes her classical message on the mixed quantum state sequence of Bell sequence SA and single photon sequence SS.Then,some single photons that are used for security check are re-inserted randomly into the encoded sequence,and the order of particles is rearranged to ensure checking Eve's attack.Alice sends the new sequence to Bob.Bob delays and receives it.And then,the quantum channel conducts the second-time security check.The transmission error rate is calculated,and if the error rate is lower than the tolerance threshold,the channel is safe.Bob decodes and reads Alice's message.The first security check is to determine whether quantum channel is safe.The second security check is to test whether there are eavesdroppers during information transmission.Safety analysis is done by applying the quantum information theory for the proposed protocol.The error rate introduced by Eve and the amount of information by Eve are calculated.It is shown that this pro-tocol can effectively resist measurement-resend attack,intercept-resend attack, auxiliary particle attack,denial of service attack and Trojan attack.Among them,auxiliary particle attack is analyzed in detail.The transmission efficiency and coding capacity are also analyzed.The transmission efficiency is 2,the quantum bit rate is 1,and the coding capacity is that a quantum state can encode three bits of classical messages.We also compare the proposed protocol with many existing popular protocols in the sense of efficiency,e.g.,Ping-Pong protocol, Deng F G et al.'s two-step and one-pad-time quantum secure direct communication protocol,Wang J et al.'s quantum secure direct communication protocol based on entanglement swapping and Quan D X et al.'s one-way quantum secure direct communication protocol based on single photon.It is proved that this proposed protocol has higher transmission efficiency.In addition,neither complex U operation nor entanglement swapping is used,and implementation process is simplified.However,this protocol is devoted to theoretical research of quantum secure direct communication.There are still some difficulties in the practical application.For example,the storage technology of quantum states is not mature at present.It is not easy to prepare and measure Bell state particles nor to combine them with single photons,and so on.The implementation of this protocol depends on the development of quantum technology in the future.
Digital interaction's expansion has created a necessity for safe and efficient data transfer. Standard encryption procedures can be cracked by sophisticated hacking techniques, and moreover, they will become obsolete in the future with the emergence of quantum computers. This article introduces a hybrid cryptography that consists of a secure channel based on quantum entanglement and a lightweight encryption scheme using XOR operations. Quantum key distribution allows for a tamper-proof key exchange, and at the same time, XOR encryption provides a very simple and quick encryption and decryption process. Thus, this double-layer security system not only ensures data privacy and data integrity but also makes it difficult for the attackers to use brute force or become one of the middle parties during the transaction. Moreover, the XOR algorithm can lower the number of calculations needed for the process, so the method can be utilized in real-time secure communication without any computational overhead. Simulation experiments are used for the evaluation of security, the time for the key generation, and the efficiency of encryption. Experiments of results underline the excellent protection of information interception and low technical overhead signalled in comparison with traditional methods of cryptography. This paper exemplifies one possible way to mix quantum and classical encryption techniques to build a secure communication system that is reliable, upgradable, and less vulnerable to attacks, which could eventually lead to a post-quantum era.