Underwater Communications and Networking Conference (UComms)
Real-Time Implementation of an Underwater Quantum Key Distribution System
Burak Kebapçı, Görkem Mutlu, İbrahim Bağlıca, Anilcan Tosun, Sude Ergin, Vecdi Emre Levent, Murat Uysal, Pietro Paglierani, Konstantinos Pelekanakis, Roberto Petroccia, João Alves
As threats in the maritime domain diversify, securing data transmission becomes critical for underwater wireless networks designed for the surveillance of critical infrastructure and maritime border protection. This has sparked interest in underwater Quantum Key Distribution (QKD). In this paper, we present a real-time implementation of an underwater QKD system based on the BB84 protocol. The QKD unit is built on a hybrid computation system consisting of an FPGA and an on-board computer (OBC) interfaced with optical front-ends. A real-time photon counting module has been implemented on FPGA. The transmitter and receiver units are powered with external UPS and all system parameters can be monitored from the connected computers. The system is also equipped with a visible laser and an alignment indicator to validate successful manual alignment.
As threats in the maritime domain diversify, securing data transmission becomes critical for underwater wireless networks designed for the surveillance of critical infrastructure and maritime border protection. This has sparked interest in underwater Quantum Key Distribution (QKD). In this paper, we present a real-time implementation of an underwater QKD system based on the BB84 protocol. The QKD unit is built on a hybrid computation system consisting of an FPGA and an on-board computer (OBC) interfaced with optical front-ends. A real-time photon counting module has been implemented on FPGA. The transmitter and receiver units are powered with external UPS and all system parameters can be monitored from the connected computers. The system is also equipped with a visible laser and an alignment indicator to validate successful manual alignment.
As threats in the maritime domain diversify, securing data transmission becomes critical for underwater wireless networks designed for the surveillance of critical infrastructure and maritime border protection. This has sparked interest in underwater Quantum Key Distribution (QKD). In this paper, we present an FPGA-based real-time implementation of an underwater QKD system based on the BB84 protocol. The QKD unit is built on a hybrid computation system consisting of an FPGA and an on-board computer (OBC) interfaced with optical front-ends. A real-time photon counting module is implemented on FPGA. The transmitter and receiver units are powered with external UPS and all system parameters can be monitored from the connected computers. The system is equipped with a visible laser and an alignment indicator to validate successful manual alignment. Secure key distribution at a rate of 100 qubits per second was successfully tested over a link distance of 7 meters.
Security is a crucial aspect of underwater acoustic networks, that are often used in mission critical scenarios, such as coastal surveillance, rapid environmental assessment and mine countermeasure applications. The broadcast nature of the acoustic channel makes it vulnerable to a variety of attacks, such as spoofing, men-in-the-middle and jamming. Moreover, the lack of a standardized key distribution system makes data confidentiality challenging. In this paper we investigate the use of quantum key distribution (QKD) in underwater networks, in order to ensure confidentiality and integrity of the communication. While in the terrestrial domain the use of the one-time-pad protocol (requiring the key length to be equal to the message length) is limited by the low rate of the QKD rate compared to the bitrate of radio transmissions, in the underwater domain the limited bandwidth of the acoustic channel makes QKD a valid approach also for the one-time-pad protocol. The system is tested both with an emulator and a field test: results show that QKD can be a valuable system to secure underwater acoustic networks.
The growing importance of Underwater Networks (UNs) in mission-critical activities at sea enforces the need for secure Underwater Communications (UCs). Classical encryption techniques can be used to achieve secure data exchange in UNs. However, the advent of Quantum Computing will pose threats to classical cryptography, thus challenging also UCs. Currently, underwater crypto-systems mostly adopt symmetric ciphers, which are considered computationally quantum-robust, but pose the challenge of distributing the secret key upfront. Post-Quantum Public-Key (PQPK) protocols promise to overcome the key distribution problem. The security of PQPK protocols, however, only relies on the assumed computational complexity of some underlying mathematical problems. Moreover, the use of resource hungry PQPK algorithms in resource-constrained environments such as UNs can require non-trivial hardware/software optimization efforts. An alternative approach is underwater Quantum Key Distribution (QKD), which promises unconditional security built upon the physical principles of Quantum Mechanics. This tutorial provides a basic introduction to free-space Underwater QKD (UQKD). At first, the basic concepts of QKD are presented, based on a fully worked out QKD example. A thorough state-of-the-art analysis of UQKD is carried out. The paper subsequently provides a theoretical analysis of the QKD performance through free-space underwater channels, and its dependence on the key optical parameters of the system and seawater. Finally, open challenges, points of strength and perspectives of UQKD are identified and discussed.
The growing importance of Underwater Networks (UNs) in mission-critical activities at sea enforces the need for secure Underwater Communications (UCs). Classical encryption techniques can be used to achieve secure data exchange in UNs. However, the advent of Quantum Computing will pose threats to classical cryptography, thus challenging also UCs. Currently, underwater crypto-systems mostly adopt symmetric ciphers, which are considered computationally quantum-robust, but pose the challenge of distributing the secret key upfront. Post-Quantum Public-Key (PQPK) protocols promise to overcome the key distribution problem. The security of PQPK protocols, however, only relies on the assumed computational complexity of some underlying mathematical problems. Moreover, the use of resource hungry PQPK algorithms in resource-constrained environments such as UNs can require non-trivial hardware/software optimization efforts. An alternative approach is underwater Quantum Key Distribution (QKD), which promises unconditional security built upon the physical principles of Quantum Mechanics. This tutorial provides a basic introduction to free-space Underwater QKD (UQKD). At first, the basic concepts of QKD are presented, based on a fully worked out QKD example. A thorough state-of-the-art analysis of UQKD is carried out. The paper subsequently provides a theoretical analysis of the QKD performance through free-space underwater channels, and its dependence on the key optical parameters of the system and seawater. Finally, open challenges, points of strength and perspectives of UQKD are identified and discussed.
The growing importance of Underwater Networks (UNs) in mission-critical activities at sea enforces the need for secure Underwater Communications (UCs). Classical encryption techniques can be used to achieve secure data exchange in UNs. However, the advent of Quantum Computing will pose threats to classical cryptography, thus challenging also UCs. Currently, underwater crypto-systems mostly adopt symmetric ciphers, which are considered computationally quantum-robust, but pose the challenge of distributing the secret key upfront. A promising approach to overcome the key distribution problem is based on Post-Quantum Public-Key (PQPK) protocols. The security of PQPK protocols, however, only relies on the assumed computational complexity of some underlying mathematical problems. Moreover, the use of resource hungry PQPK algorithms in resource-constrained environments such as UNs can require non-trivial hardware/software optimization efforts. An alternative approach is underwater Quantum Key Distribution (QKD), which promises unconditional security built upon the physical principles of Quantum Mechanics. This tutorial provides a basic introduction to free-space Underwater QKD (UQKD). At first, the basic concepts of QKD are presented, based on a fully worked out QKD example. A thorough state-of-the-art analysis of UQKD is carried out. The paper subsequently provides a theoretical analysis of the QKD performance through free-space underwater channels, and its dependence on the key optical parameters of the system and seawater. Finally, open challenges, points of strength and perspectives of UQKD are identified and discussed.
Quantum key distribution (QKD) provides a secure and effective way of exchanging cryptographic symmetric keys without the possibility of an eavesdropper being undetected. The transmission and detection of the quantum states at the physical layer is the first step to defining a common source of entropy, where both parties will extract a raw key. Over the last few years, continuous variable quantum key distribution (CV-QKD) protocols have become an attractive technology for QKD, providing a low-cost solution that can be easily integrated with the current optical network devices and infrastructure. Unlike other QKD technologies, a CV protocol requires complex and highly computationally demanding digital signal processing (DSP) operations. In that sense, parallel computation tools such as field programmable gate arrays (FPGAs) represent a key element for the practical implementation of this quantum technology and to scale its performance in terms of distance and secret key rate indicators. This work presents an FPGA-based implementation of the physical layer of a CV-QKD transmitter. The proposed architecture and employed protocols are described, and hardware implementation aspects are discussed, including resource occupation analysis, configuration parameters, and timing issues.