In a recent article, Chang et al. proposed a quantum secure direct communication protocol using single photons (Chinese Sci Bull, 58: 4571-4576). The protocol is equipped with authentication. In this article we present a novel attack on the protocol that can determine the secret key which is already shared between Alice and Bob.
We analyze the security of a quantum secure direct communication protocol equipped with authentication. We first propose a specifc attack on the protocol by which, an adversary can break the secret already shared between Alice and Bob, when he (adversary) runs the protocol few times. The attack shows that there is a gap in authentication procedure of the protocol, and by doing so the adversary can obtain the key without remaining any trace. We then give the modification of the protocol and analyze the security of it, and show how the modified protocol can close the gap.
Abstract Recently, Yan et al . proposed a quantum secure direct communication (QSDC) protocol with authentication using single photons and Einstein-Podolsky-Rosen (EPR) pairs ( Yan L. et al ., Comput. Mater. Contin. , 63 (2020) 1297). In this work, we show that the above QSDC protocol is secure neither against intercept-and-resend attack, nor against impersonation attack. With any of these two types of attacks, an eavesdropper can recover the full secret message. We also propose a suitable modification of this protocol, which not only defeats the above attacks, but also resists all other common attacks. Thus, our modified protocol provides an improvement over the existing one in terms of security.
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.
A quantum high secure direct communication with authentication protocol is proposed by using single photons. The high security of the protocol is achieved on levels. The first level involves the verification of the quantum channel security by using fake photons. The authentication process is also ensured by the fake photons. The second level of security is given by the use of multiple polarization bases. The secret message is encoded in groups of photons; each single character of the message is associated with m (m≥7) photons. Thus, at least 27(128) characters will be encoded. In order to defeat the quantum teleportation attack, the string of bits associated to the secret message is encrypted with a secret string of bits by using XOR operator. Encryption of the sender's identity string and the receiver's identity string by the XOR operator with a random string of fake photons defends quantum man-in-the-middle attack efficiently. Quantum memory is required to implement our protocol. Storage of quantum information is a key element in quantum information processing and provides a more flexible, effective and efficient communication. Our protocol is feasible with current technologies.
Quantum secure direct communication (QSDC) enables secure message transmission without needing pre-shared keys. To enhance the practical reliability of QSDC systems, measurement-device-independent (MDI) protocols have emerged, providing robust security in real-world applications. Despite the advantages of MDI protocols, their implementation has not yet accomplished communication using only single photons which are advantageous due to their ease of preparation and transmission. In this letter, by employing single photons, we propose a novel MDI-QSDC protocol with identity authentication. This protocol achieves mutual identity authentication between the communicating parties, Alice and Bob, enabling authenticated Alice to securely transmit her secret message directly to authenticated Bob. Theoretical analysis demonstrates the protocol is resilient to identity and message security threats. Simulations with practical experimental parameters and efficiency analysis highlight its potential in quantum communication.
In this paper we propose two quantum secure direct communication (QSDC) protocols with authentication. The authentication key expansion method is introduced to improve the life of the keys with security. In the first scheme, the third party, called Trent is introduced to authenticate the users that participate in the communication. He sends the polarized photons in blocks to authenticate communication parties Alice and Bob using the authentication keys. In the communication process, polarized single photons are used to serve as the carriers, which transmit the secret messages directly. The second QSDC process with authentication between two parties is also discussed.