Quantum Indirect Communication with Secure Transmission Mechanisms

Recently, on the basis of advanced development in quantum transmission technology and quantum key distribution, the advanced techniques of quantum cryptography can be applied to the different security issues, including quantum authentication, quantum secure communication, quantum detection, quantum secure transmission and quantum signature. These applications let that quantum information networks will become realistic in the future.
Compared with quantum cryptography and classical cryptography, the major difference comes from the laws of physics. Quantum channel is based on the laws of physics such as uncertainty principle, no-cloning theorem and quantum teleportation. These physical properties make quantum channel is more secure than classical channel. By using physical properties of quantum channel, we can detect eavesdropping and support secure direct communication. However, classical cryptography can not detect the presence of eavesdroppers, especially with wireless open medium. In regard to the time complexity, quantum cryptography algorithm based on the laws of physics is better than classical cryptography algorithm based on mathematical computation. For example, in the factoring problem, time complexity of quantum algorithm is polynomial time. Compared with classical cryptography algorithm, its time complexity is exponential.
Compared with previous quantum researches, these applications used quantum key distribution protocols such as BB84 and E91 to generate a secret key which can be used to achieve transmission integrity in the direct communication. However, in general, the connection type of transmitting message is indirect communication. Under the indirect communication, transmitting message from source to destination may pass through several intermediate nodes and communication channels. In the routing path, there are three types of attacks, including eavesdropping, man-in-the-middle attacks and malicious node. It is called an unsafe routing path. Under an unsafe routing path, we can not pursue the secure routing path to transmit quantum message. It is a difficult work to resist the previous attacks and get the secure transmission process for quantum indirect communication.
For quantum indirect communication, this dissertation is to design several transmission mechanisms which are used to achieve the data security. This work includes the following parts. For quantum authentication, we present two types of quantum authentication mechanism that can solve the identification problem between the sender and receiver under the unsafe routing path. Two remote parties can achieve the secure authentication process to resist eavesdropping and malicious node. On the basis of the laws of physics, the secure authentication process can be achieved. For quantum detection, the sender and receiver can use quantum entangled qubits and a collaborative working circuit to detect the intrusive behavior of malicious node. Based on this circuit, the receiver can obtain the original quantum state of sending quantum qubits such that the intrusive behavior of malicious node can be detected.
For quantum transmission, three quantum transmission mechanisms are proposed to achieve transmission integrity under an unsafe routing path. These mechanisms can resist three types of attacks and let the receiver has the capability to judge whether the receiving quantum frame is complied with the security requirement and can be accepted or not. This is a new breakthrough. For quantum signature, client and server can use the property of quantum secret sharing to secure the signature process for indirect communication. If the developed techniques of these applications are mature, then the proposed quantum transmission mechanisms can guarantee that the quantum message can be securely transmitted in the quantum indirect communication.