Introduction to special issue on secure quantum communication

Abstract

This special issue on secure quantum communication was proposed to us by Dr. Howard Brandt, then Editor of Quantum Information Processing, and we would like to take this opportunity to commemorate his contributions to quantum physics and quantum cryptography over his many years of service in various roles. We had the understanding that this special issue may be broader in scope than strictly “quantum” and “communication”, to include related topics that bear on “secure quantum communication” in one way or another, such as classical noise protocol and quantum bit commitment. A total of twenty-six papers were submitted and twelve were accepted. Quantum key distribution (QKD) is widely considered the most mature area of quantum information science and especially technology. The typical perception [1] is that long perfect key bits can be generated between two users in the information theoretic sense, in contrast to the unproved complexity-based security of public key cryptography. However, the probabilistic foundation of such claim is shakier than it may first appear and the numerical security levels that can be obtained experimentally and theoretically are far from adequate [2]. We do not go into such dispute in this special issue, but in the paper of Yuen, some physics and systems security issues that have been neglected in the QKD literature are noted. Another case of QKD protocol’s