The Status of Quantum-Key-Distribution-Based Long-Term Secure Internet Communication

A large amount of sensitive data must remain accessible for decades or even centuries (e.g, electronic health records, governmental documents). Communicating such data over the Internet requires long-term secure communication channels, which, in turn, require robust key distribution protocols. Currently used key distribution protocols, however, are not designed for long-term security. Their security is either threatened by quantum computers, or, in principle, due to their reliance on computational problems. Quantum key distribution (QKD) protocols are information-theoretically secure and thereby offer long-term security against computational attacks. However, significant obstacles to their real-world use remain. This position paper, which is a multidisciplinary effort of computer scientists and physicists, systematizes knowledge about challenges of and strategies for realizing long-term secure Internet communication from QKD. We first analyze the performance and security of existing point-to-point QKD technology. Then, we discuss several approaches to enabling QKD in large-scale multi-user networks. Finally, we list important challenges that need to be addressed in order to make QKD-based long-term secure communication on the Internet practical.