100 Gbps quantum-secured and O-RAN-enabled programmable optical transport network for 5G fronthaul

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 systemas 10 Gbps fronthaul interface was stressed with a large Ethernet frame (1500B) at a rate of ${\approx} 9.8\;{\rm Gbps}$ with 300,000 Internet Control Message Protocol pings, and less than 1% data loss was observed.