## 1 Introduction  
With the continuous development of network and communication technologies, there is inevitably a large amount of private and sensitive information being transmitted in the existing network communication environment. However, the emergence and constant breakthroughs of quantum computing technology and quantum computers pose a threat to the security of data protection in traditional cryptography [1, 2]. Traditional encryption algorithms mainly rely on the difficulty of mathematical problems, such as factorization and discrete logarithms. The attack of quantum computing on traditional encryption algorithms is primarily based on the quantum parallelism and quantum search algorithms possessed by quantum computers. Traditional encryption algorithms like RSA encryption are secured based on the difficulty of factorizing large numbers, where one important step is to choose two large prime numbers as part of the private key [3]. Classical computers currently lack the efficient means to factorize large numbers. However, in quantum computing, [PERSON]'s algorithm is a quantum algorithm proposed by [PERSON] [4], which can efficiently perform factorization on quantum computers. By utilizing [PERSON]'s algorithm, quantum computers can quickly factorize the large numbers used in RSA encryption and thus break the RSA encryption algorithm [5]. Similarly, Elliptic Curve Cryptography (ECC) is a commonly used symmetric encryption algorithm in modern cryptography, which exploits the difficulty of operations on points on elliptic curves [6]. Traditional computers require a long time to break ECC encryption; however, [PERSON]'s algorithm is a quantum search algorithm that can accelerate the search for solutions on quantum computers. By applying [PERSON]'s algorithm, quantum computers can effectively reduce the search space and find the private key of the ECC encryption algorithm in a shorter time, thereby breaking the encryption [7]. To counter the threat of quantum computing to traditional cryptography, two new encryption methods have emerged: Post-Quantum Cryptography (PQC) and Quantum Key Distribution (QKD) [8; 9; 10]. PQC is different from traditional encryption algorithms based on mathematical problems as it mainly relies on other difficult problems such as lattice problems, polynomial ring problems, and coding problems. The goal of PQC is to provide security comparable to that of traditional encryption algorithms and to withstand attacks by quantum computers [8]. QKD is a method of using quantum mechanics principles to achieve encrypted key transmission. As one of the most successful applications of quantum cryptography, QKD promises information-theoretic security based on quantum physics laws for distributing symmetric keys between a pair of legitimate parties. Then, symmetric key cryptographic systems can use these keys to encrypt confidential messages transmitted over a public channel. One example of symmetric key cryptographic systems is the so-called one-time pad (OTP), which [PERSON] has proved to help in secure message encryption in information theory. However, its disadvantage is that the key must be at least as long as the message. Of course, shorter keys can also be used through some methods; other symmetric key cryptographic systems, such as the Advanced Encryption Standard (AES), are also considered quantum-safe. A key challenge faced by symmetric key cryptographic systems is secure key sharing, which QKD can bypass. In recent years, point-to-point QKD technology has made significant progress in protocols, devices, systems, and so on to improve QKD performance, which can be quantified in terms of the key rate, distance, and security. Therefore, QKD systems have been commercially available in the market. With the arrival of the 5G communication era and the continuous development of 6G communication technology, quantum networks built with related quantum communication technologies such as QKD are likely to become an important part of future networks [11; 12; 13].