Based on mutual authentication and dense coding, a novel revised efficient quantum direct communication scheme is proposed. It is composed of two phases: the quantum state distribution process and the direct communication process. The purpose of the former is to authenticate Trent and users to each other, and let the two legitimate users (Alice and Bob) safely share the Bell states. While the latter aims to make direct communication to transmit a secret message between Alice and Bob. In order to prevent from Eve's eavesdropping as well as to authenticate each other simultaneously, a decoy photon checking technique is applied. Compared with other analogous protocols, the quantum state distribution process is more simple and feasible and the proposed scheme is more efficient; i.e., the total efficiency is almost 100%. Security analysis shows that the proposed scheme is secure against the eavesdropping attacks, the impersonation attacks, and some special Trent's attacks, including the attacks by using different initial states.
Based on mutual authentication and dense coding, a novel revised efficient quantum direct communication scheme is proposed. It is composed of two phases: the quantum state distribution process and the direct communication process. The purpose of the former is to authenticate Trent and users to each other, and let the two legitimate users (Alice and Bob) safely share the Bell states. While the latter aims to make direct communication to transmit a secret message between Alice and Bob. In order to prevent from Eve's eavesdropping as well as to authenticate each other simultaneously, a decoy photon checking technique is applied. Compared with other analogous protocols, the quantum state distribution process is more simple and feasible and the proposed scheme is more efficient; i.e., the total efficiency is almost 100%. Security analysis shows that the proposed scheme is secure against the eavesdropping attacks, the impersonation attacks, and some special Trent's attacks, including the attacks by using different initial states.
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.
In response to the demand for identity authentication in quantum secure direct communication, this paper proposes a quantum secure direct communication scheme based on a mixture of single photon and Bell state, by combining the bidirectional identity authentication. Before communication begins, both parties share a series of secret information to prepare a series of single photon and Bell state particles. Encoding four single photons and four Bell states yields eight types of encoded information, followed by identity authentication. The first step in identity authentication is to use a single photon to verify the legitimacy of the receiver. If the error exceeds the given threshold, it indicates the presence of eavesdropping. Otherwise, the channel is safe. Then, Bell state particles are used to verify the legitimacy of the sender, and the threshold is also used to determine whether there is eavesdropping. The present method is the same as previous one. If the error rate is higher than the given threshold, it indicates the existence of third-party eavesdropping. Otherwise, it indicates that the channel is secure. As for the specific verification method, it will be explained in detail in the article. Afterwards, Bell state particles are mixed with a single photon as a transmission carrier, and eavesdropping detection particles are added whenever the quantum state is sent. However, once the eavesdropper intercepts the transmitted particles, owing to incomplete information obtained, the eavesdropper is unable to recover the original information, and the eavesdropping behavior will be immediately detected, thus terminating communication. In this scheme, single photon and Bell states are fully utilized, and hybrid communication can effectively improve transmission efficiency, encoding capability, and quantum bit utilization. Security analysis shows that this scheme can resist common external and internal attacks such as interception/measurement replay attacks, auxiliary particle attacks, and identity impersonation attacks. The analysis of efficiency and encoding capacity shows that the transmission efficiency of this scheme is 1, the encoding capacity is 3 bits per state, and the quantum bit utilization rate is 1. Compared with other schemes, this scheme has significant advantages because it uses different particles for bidirectional authentication, making it more difficult for attackers to crack, and thus it has higher security than traditional schemes.
The three-dimension Qutrit, unitary operation and non-orthogonal measurement basis were defined, and a novel quantum secure direct communication scheme based on three-dimension single photon and mutual authentication was proposed. The present scheme is composed of Qutrits sending and returning procedures, the users would make identity authentication with each other in order to ensure users’ legality. The secret message is encoded on batches of Qutrits based on unitary operation, and is sent through the Qutrits returning procedure. Security analysis shows that this scheme can efficiently resist all kinds of eavesdropper Eve attacks and the impersonator attacks. The scheme inherits the advantages of the single photon protocols, practical and economic within the present technology. Comparing with those two-dimension single photon protocols, it shows more efficient with 1.5 times of the transmission efficiency.
Unconditional security in Quantum Key Distribution (QKD) relies on authenticating the identities of users involved in key distribution. While classical identity authentication schemes were initially utilized in QKD implementations, concerns regarding their vulnerability have prompted the exploration of Quantum Identity Authentication (QIA) protocols. In this study, we introduce a new protocol for QIA, derived from the concept of controlled secure direct quantum communication. Our proposed scheme facilitates simultaneous authentication between two users, Alice and Bob, leveraging Bell states with the assistance of a third party, Charlie. Through rigorous security analysis, we demonstrate that the proposed protocol withstands various known attacks, including impersonation, intercept and resend and impersonated fraudulent attacks. Additionally, we establish the relevance of the proposed protocol by comparing it with the existing protocols of similar type.
In this paper, a novel authenticated quantum secure direct communication scheme with three-dimension single photons is presented, where the message is encoded on batches of qutrits, and identity is mutual authenticated with their shared seed key. Security analysis shows that this scheme can efficiently resist Eve's attacks and the impersonator's attacks. Comparing with those protocols using entangled state, the presented scheme is more practical and economic within the present technology.
In this paper, we first point out that some recently proposed quantum direct communication (QDC) protocols with authentication are vulnerable under some specific attacks, and the secrete message will leak out to the authenticator who is introduced to authenticate users participating in the communication. We then propose a new protocol that is capable of achieving secure QDC with authentication as long as the authenticator would do the authentication job faithfully. Our quantum protocol introduces a mutual authentication procedure, uses the quantum Bell states, and applies unitary transformations in the authentication process. Then it exploits and utilizes the entanglement swapping and local unitary operations in the communication processes. Thus, after the authentication process, the client users are left alone to communicate with each other, and the authenticator has no access to the secrete message. In addition, our protocol does not require a direct quantum link between any two users, who want to communicate with each other. This may also be an appealing advantage in the implementation of a practical quantum communication network.