Observations from Quantum Cryptography Conference (QCrypt) 2015
Over the past several years, the annual QCrypt conference has served as the world’s premier forum for students and researchers to present and collaborate on all aspects of quantum cryptography. QCrypt is also the primary forum for announcing the year’s best QKD results. In late 2015, the fifth QCrypt conference was hosted in Tokyo, Japan and attended by more than 275 participants with a largely international audience of physicists, information theorists, and cryptographers (Quantum Cryptography Conference, 2016). From this conference, key observations are offered for the reader to gain perspective on recent developments in the quantum cryptography field.
- Striving for Commercial Viability – QCrypt 2105 began with several demonstrations and talks focused on practically-oriented QKD systems which balance cost, performance, and security trades towards affordability. In particular, the QKD industry leader, ID Quantique, unveiled a completely redesigned QKD blade system which employs a new quantum exchange protocol, anti-tamper precautions, and additional security features to mitigate quantum attacks (ID Quantique, 2016). Likewise, Toshiba Research Laboratory Europe, supported by Japan’s National Institute of Information and Communications Technology, prominently displayed their record breaking QKD system. The Toshiba system boasts the world’s highest key rates, improved user interface, and automated synchronization for increased usability over metropolitan distances (Dixon, et al., 2015). Unlike early experimental QKD configurations, these systems are designed to be rack mountable and more easily integrate into existing communications structures. Figure 3 shows both the commercially viable ID Quantique and Toshiba QKD systems.
Figure 3. The ID Quantique (IDQ) rack mountable QKD system is shown on the top (ID Quantique, 2016) and the Toshiba record holding hybrid QKD system is shown on the bottom (Dixon, et al., 2015).
- Fielding QKD Networks – For distributed networks and long distance operation, QKD requires the use of either quantum repeaters or satellite-based solutions. While fully functional quantum repeaters are years away from being realized, simpler stop-gap “trusted node” configurations have been successfully fielded (Scarani, et al., 2009). These QKD networks utilize a series of back-to-back QKD systems to cover larger metropolitan areas and support long-haul backbone distances. Using this method, China is building the world’s largest QKD network along its west coast employing 46 nodes to cover some 2,000 km (Wang, et al., 2014). Similarly, one of the conference’s keynotes, the US research organization Battelle, described their development of trusted nodes with ID Quantique to support a 1,000 km planned run from Columbus, Ohio to Washington, D.C. (Quantum Cryptography Conference, 2016). With respect to satellite-to-ground QKD, research centers in America, Canada, Europe, Japan, and China are exploring the feasibility of and conducting experiments to prove the feasibility of transmitting single photons from a Low Earth Orbit (LEO) satellite through the Earth’s turbulent atmosphere. Most notably, China is actively pursuing their goal of launching a QKD satellite by 2016 (Bieve, 2016). Figure 4 depicts both China’s terrestrial QKD network and their planned space-based QKD links.
Figure 4. China’s 46 node terrestrial QKD network is shown on the left and the planned space-based QKD network is shown on the right (Quantum Cryptography Conference, 2016).
- Barriers to Acceptance – While a majority of the research-focused conference is focused on improvements to QKD protocols, quantum hardware, and information theory advancements, arguably, the most important theme of the conference pertained to the acceptance of QKD (or lack thereof) as a cybersecurity solution. As repeatedly recognized during QCrypt 2015, several significant barriers to QKD’s acceptance exist. This was perhaps best captured by the field’s most recognized researcher, Dr. Nicolas Gisin, who boldly stated “The quantum technology era has started… In 10 years either QKD will have found its markets or will be dead” (Gisin, 2015). In a cybersecurity community that typically adopts new technological solutions rather quickly, quantum based security technologies are slow to be adopted. Perhaps, security professionals are uncomfortable with the topic of quantum mechanics? Or perhaps, QKD developers are just now starting to make progress on critical implementation security issues, interoperability standards, and formal certifications (ETSI, 2015).
From these overarching conference themes, we next elaborate on some of QKD’s advantages and disadvantages in order to help security professionals better understand the technology and its application. Thus, while a bit subjective in nature, and not without debate, we’ve chosen to describe three ways in which QKD is a boon to the cybersecurity community and three ways in which it is a bust.