Secure quantum communication traditionally assumes that the adversary controls only the public channel. We consider a more powerful adversary who can demand private information of users. This type of adversary has been studied in public key cryptography in recent years, initiated by Persiano, Phan, and Yung at Eurocrypt 2022. We introduce a similar attacker to quantum communication, referring to it as the controller. The controller is a quantum computer that controls the entire communication infrastructure, including both classical and quantum channels. It can even ban classical public key cryptography and post-quantum public key cryptography, leaving only quantum cryptography and post-quantum symmetric key cryptography as the remaining options. We demonstrate how such a controller can control quantum communication and how users can achieve covert communication under its control.
Secure quantum communication traditionally assumes that the adversary controls only the public channel. We consider a more powerful adversary who can demand private information of users. This type of adversary has been studied in public key cryptography in recent years, initiated by Persiano, Phan, and Yung at Eurocrypt 2022. We introduce a similar attacker to quantum communication, referring to it as the controller. The controller is a quantum computer that controls the entire communication infrastructure, including both classical and quantum channels. It can even ban classical public key cryptography and post-quantum public key cryptography, leaving only quantum cryptography and post-quantum symmetric key cryptography as the remaining options. We demonstrate how such a controller can control quantum communication and how users can achieve covert communication under its control.
Quantum networks rely on both quantum and classical channels for coordinated operation. Current architectures employ entanglement distribution and key exchange over quantum channels but often assume that classical communication is sufficiently secure. In practice, classical channels protected by traditional cryptography remain vulnerable to quantum adversaries, since large-scale quantum computers could break widely used public-key schemes and reduce the effective security of symmetric cryptography. This perspective presents a quantum-resistant network architecture that secures classical communication with post-quantum cryptographic techniques while supporting entanglementbased communication over quantum channels. Beyond cryptographic protection, the framework incorporates continuous monitoring of both quantum and classical layers, together with orchestration across heterogeneous infrastructures, to ensure end-to-end security. Collectively, these mechanisms provide a pathway toward scalable, robust, and secure quantum networks that remain dependable against both classical and quantum-era threats.
Computational encryption, information-theoretic secrecy and quantum cryptography offer progressively stronger security against unauthorized decoding of messages contained in communication transmissions. However, these approaches do not ensure stealth--that the mere presence of message-bearing transmissions be undetectable. We characterize the ultimate limit of how much data can be reliably and covertly communicated over the lossy thermal-noise bosonic channel (which models various practical communication channels). We show that whenever there is some channel noise that cannot in principle be controlled by an otherwise arbitrarily powerful adversary--for example, thermal noise from blackbody radiation--the number of reliably transmissible covert bits is at most proportional to the square root of the number of orthogonal modes (the time-bandwidth product) available in the transmission interval. We demonstrate this in a proof-of-principle experiment. Our result paves the way to realizing communications that are kept covert from an all-powerful quantum adversary.
The potential of the swift development of quantum computing is an extreme danger to the traditional cryptographic programs, and they are the foundation of the modern communication infrastructure. RSA and ECC are classical public-key algorithms that can be successfully quantum-attacked, in particular, Shor's algorithm can easily factor large integers and calculate discrete logarithms (Bernstein et al., 2017). The Post-Quantum Cryptography (PQC) has become the key to secure the next-generation communication networks against these threats, which relies on lattice problem-based algorithms, hash-based based algorithms, multivariate polynomials-based algorithms, and code-based cryptography. The paper examines the concepts, design, and implementation issues of PQC within current network infrastructure focusing on the secure transmission of data, authentication, and key management in the upcoming 5G and 6G networks. The approach will include the survey of existing algorithms of PQC, model the integration of protocol in the communication systems and test computational efficiency, security strength, and scalability. It has been found that PQC is suitable to protect network communications against quantum attackers, and achieves reasonable performance, though trade-offs can be seen in terms of computation overhead, key size, and latency. The research offers understanding to the researcher, network engineers and policy makers in order to adopt quantum resistant cryptography protocols to secure the confidentiality, integrity and authenticity of information in the future communication networks.
Classical cryptography methods are becoming susceptible to quantum attacks like those implemented by Shor and Grover algorithms and can break RSA and symmetric-key encryption. Traditional communication channels are also susceptible to interception and even modification of the signal that causes data confidentiality to be compromised. In order to overcome these limitations, this paper proposes a three-layer quantum-hybrid communication framework, which integrates entanglement-based QKD, multi-channel redundancy, and steganographic hiding. The framework improves the security with an entanglement-assisted BB84-based protocol, the reliability with the help of multi-channel qubit transmission, and covert transmission with LSB/DCT-image embedding. The framework is developed and implemented as a simulator in Python using Qiskit, NumPy, and OpenCV and showed better Bit Error Rate (BER), SSIM, fidelity and security strength than classical systems. The proposed architecture mitigates key vulnerabilities in cryptographic strength, transmission stability, and communication detectability, providing a robust foundation for quantum-resilient and covert communication.
Existing network cryptography systems are threatened by recent developments in quantum computing. For example, the Shor algorithm, which can be run on a quantum computer, is capable of overriding public key-based network cryptography systems in a short time. Therefore, research on new cryptography systems is actively being conducted. The most powerful cryptography systems are quantum key distribution (QKD) and post quantum cryptograph (PQC) systems; in this study, a network based on both QKD and PQC is proposed, along with a quantum key management system (QKMS) and a Q-controller to efficiently operate the network. The proposed quantum cryptography communication network uses QKD as its backbone, and replaces QKD with PQC at the user end to overcome the shortcomings of QKD. This paper presents the functional requirements of QKMS and Q-Controller, which can be utilized to perform efficient network resource management.
The development of quantum computers poses a new security threat to network infrastructures and services, as they will be powerful enough to break the most common forms of digital encryption. Existing encryption services based on Rivest–Shamir–Adleman (RSA), Diffie-Hellman (DH), Elliptic Curve Cryptography (ECC) and so on are vulnerable to attacks by quantum computers. Although the gap between today’s quantum computers and the threats they pose to current public-key cryptography is large, the telecommunications landscape should begin planning for the transition to the post-quantum era as early as possible. In this paper, we examine recent advances in Post Quantum Cryptography (PQC) algorithms from the perspective of the networking and telecommunications industries. The efforts are categorized at three levels, namely communication, computation (consisting of design, implementation and Public Key System (PKS)), and network. Some of the existing challenges and future recommendations for securing communication networks in the post-quantum era are also listed at the end of the paper.