A quantum-secured packetized optical fronthaul segment is thoroughly discussed. We present an extensive study on the integration of a Discrete Variable-Quantum Key Distribution (DV-QKD) link supporting the Advanced Encryption Standard-256 (AES-256) encryption of packetized fronthaul operating at 10Gbps. Secure key rates exceeding the 1Kbps and short rotation times down to 1.4s are reported for Point-to-Point (P2P) topologies by considering the latency budget of 5G fronthaul connectivity. For the multi-user environment, the Bob stations implementation of quantum layer is adapted to satisfy the connectivity needs of Point-to-Multipoint (P2MP) scenario, allowing for successful distribution of AES-256 keys to N=16 5G terminal nodes with ultra-low attack success probabilities of less than 2-60.
A quantum-secured packetized optical fronthaul segment is thoroughly discussed. We present an extensive study on the integration of a Discrete Variable-Quantum Key Distribution (DV-QKD) link supporting the Advanced Encryption Standard-256 (AES-256) encryption of packetized fronthaul operating at 10Gbps. Secure key rates exceeding the 1Kbps and short rotation times down to 1.4s are reported for Point-to-Point (P2P) topologies by considering the latency budget of 5G fronthaul connectivity. For the multi-user environment, the Bob stations implementation of quantum layer is adapted to satisfy the connectivity needs of Point-to-Multipoint (P2MP) scenario, allowing for successful distribution of AES-256 keys to N=16 5G terminal nodes with ultra-low attack success probabilities of less than 2-60.
A research contribution focusing on the Quantum Key Distribution (QKD)-enabled solutions assisting in the security framework of an optical 5G fronthaul segment is presented. We thoroughly investigate the integration of a BB84-QKD link, operating at telecom band, delivering quantum keys for the Advanced Encryption Standard (AES)-256 encryption engines of a packetized fronthaul layer interconnecting multiple 5G terminal nodes. Secure Key Rate calculations are studied for both dedicated and shared fiber configurations to identify the attack surface of AES-encrypted data links in each deployment scenario. We also propose a converged fiber-wireless scenario, exploiting a mesh networking extension operated by mmWave wireless links. In addition to the quantum layer performance, emphasis is placed on the strict requirements of 5G-oriented optical edge segments, such as the latency and the availability of quantum keys. We find that for the dark fiber case, secret keys can be distilled at fiber lengths much longer than the maximum fiber fronthaul distance corresponding to the round-trip latency barrier, for both P2P and P2MP topologies. On the contrary, the inelastic Raman scattering makes the simultaneous transmission of quantum and classical signals much more challenging. To counteract the contamination of noise photons, a resilient classical/QKD coexistence scheme is adopted. Motivated by the recent advancements in quantum technology roadmap, our analysis aims to introduce the QKD blocks as a pillar of the quantum-safe security framework of the 5G/B5G-oriented fronthaul infrastructure.
We have successfully demonstrated the first 5G open radio access network (O-RAN)-enabled and quantum-secured optical network solution and tested its performance in a 5G fronthaul use case. Our proposed solution is unique in a way that it combines a quantum key distribution (QKD)-compatible on-demand programmable 100 Gbps Ethernet encryptor with multi-tenant network operation while satisfying the stringent timing requirements of the 5G O-RAN with ultra-low pipeline latency. Moreover, our encryption cores provide the fastest reconfiguration speeds with the highest transmission capacity. By using dynamic reconfiguration technology, encryption schemes can be switched between Advanced Encryption Standard (AES) variations AES-256, AES-192, and AES-128 and Camellia-256, XOR, or no-encryption configurations in 16.7 ms for encryption and 24.1 ms for decryption. Furthermore, the key slicing functionality was introduced to our system, allowing users to have their separate key storages within the field programmable gate array and different key exchange schemes or refresh rates per client, where a secret key rate of 1.6 keys/s per client for less than 10 Gb of encrypted data could be provided. With encryption, the lowest system latency of 817.6 ns was achieved. Without encryption, the system latency could be as low as 667.2 ns. When our proposed system was tested in 5G fronthaul where our design was placed between a 5G radio unit and a 5G distributed unit/central unit, and the traffic between the 5G customer premises equipment and 5G core user plane function was transported and encrypted by our system over 100 Gbps, no significant impact on network latency on the millisecond scale was observed. Our system’s 10 Gbps fronthaul interface was stressed with a large Ethernet frame (1500B) at a rate of ≈9.8Gbps with 300,000 Internet Control Message Protocol pings, and less than 1% data loss was observed.
In the digital age, 5G technology has significantly enhanced global communication capabilities, providing strong support for various industries. However, 5G falls short of achieving comprehensive intelligence within the Internet of Things (IoT), propelling the development of 6G technology. 6G is expected to further enhance network performance by integrating advanced technologies such as AI and quantum communication, while expanding application scenarios to include communication in extreme environments for comprehensive global connectivity. This paper proposes an innovative fronthaul architecture that applies Quantum Key Distribution (QKD) technology to the 5G fronthaul, leveraging its unconditionally secure key generation and distribution mechanism. In this design, costlier Alice devices are placed on the AAU side, while less expensive Bob devices are positioned on the DU side, optimizing deployment to reduce engineering costs and lower deployment barriers. The feasibility of this architecture is demonstrated by calculating the secure key rate. Comparative analysis with existing research is performed to clarify future research directions. These innovations not only enhance 5G network security but also offer new solutions for the security requirements of 6G networks, such as data security, network resilience, and algorithm transparency. Our research offers strategic value for future network security, laying the groundwork for reliable networks.
The rapid evolution of mobile communication technology from 5G to 6G brings great opportunities but also poses serious security and privacy challenges. Although 6G networks offer advantages such as ultra-low latency, extremely high data rates, and massive connectivity, their decentralized, AI-driven, and highly virtualized architecture makes them more vulnerable to cyber-attacks. Traditional encryption methods are increasingly incapable of defending against emerging attacks. To address this issue, this paper proposes an innovative quantum-secured passive WDM fronthaul architecture that integrates BB84-based Quantum Key Distribution (QKD) with existing WDM fiber communication technology, balancing high security with feasibility. The architecture adopts an asymmetric design: low-cost quantum transmitters are deployed at distributed AAU sites, while high-performance quantum receivers are centrally installed at DU sites. This significantly reduces hardware costs and simplifies large-scale deployment. In addition, a centralized Key Management Center (KMC) is introduced to enable dynamic key distribution and real-time updates, further enhancing the system’s security and operational efficiency. Simulation results show that under a fiber attenuation of 0.20 dB/km and a detection efficiency of 10%, the system can maintain a relatively high secure key rate and an acceptable quantum bit error rate (QBER) over a transmission distance of 170 km. Furthermore, by optimizing key parameters such as detection efficiency, fiber attenuation coefficient, and the average photon number per pulse, the system’s key generation rate and secure transmission distance can be further improved.
The transition from 5G to 6G networks introduces significant advancements in speed, latency, and connectivity, but also raises critical security concerns. The increasing number of devices that need to be plugged into the network makes the demand for enhanced security and efficiency paramount. This paper proposes a novel Quantum-Encrypted 6G Fronthaul Network Architecture, integrating quantum communication with passive wavelength division multiplexing technology to address the security challenges in next-generation networks. The architecture ensures theoretically unbreakable encryption by utilizing quantum key distribution techniques on top of the current passive WDM fronthaul network architecture. It reduces the difficulty and cost of network upgrades while maintaining high bandwidth utilization and scalability. By deploying quantum communication devices in Active Antenna Units and Distributed Units, the proposed system enhances the security of the fronthaul link, protecting against eavesdropping and cyber attacks. The results obtained through simulation demonstrate that the system is highly resistant to dark counts, detection efficiency, and photon pulse variations, ensuring reliable key distribution over long distances. This architecture not only provides a cost-effective upgrade path for existing 5G networks but also paves the way for secure, high-capacity communication in future 6G applications, such as autonomous systems, smart cities, and critical infrastructure.
With the global deployment of 5G networks, the demand for high bandwidth and low latency has driven innovations in fronthaul architectures. However, traditional solutions face challenges related to security and signal interference. This paper proposes an innovative quantum-enhanced converged wireless-fiber 5G fronthaul system that integrates quantum key distribution (QKD) technology with a passive wavelength division multiplexing (WDM) architecture to achieve physical-layer secure communication. The system deploys the quantum transmitter (Alice) at the active antenna unit (AAU) side and the receiver (Bob) at the distribution unit (DU) side, leveraging the Heisenberg Uncertainty Principle, quantum measurement collapse theory, and the no-cloning theorem to detect eavesdropping attempts. Simulation results demonstrate the significant impact of noise detection probability, fiber loss, and transmission distance on both the secure key rate and quantum bit error rate (QBER). Key findings highlight the need to minimize fiber loss, reduce transmission distance, lower filter loss, decrease noise detection probability, and improve detection efficiency. These optimizations collectively enhance the secure key rate while reducing the QBER, thereby improving overall system reliability. Remarkably, this solution achieves these security enhancements without requiring large-scale modifications to existing infrastructure, offering a practical and cost-effective upgrade path for current 5G deployments while providing a future-proof foundation for emerging 6G networks. The architecture’s inherent scalability and compatibility make it particularly suitable for high-security applications, including government communications, financial transactions, and critical infrastructure protection—bridging the gap between theoretical quantum security and practical wireless network implementation.