1.9.2017 10.30-11.30 QA,
(University of Waterloo)
Building quantum internet
The history of cryptography is a history of failures. Stronger ciphers replaced broken ones, to be in turn broken again. Quantum cryptography is offering a hope to end this replacement cycle, for its security premises on the laws of quantum physics and not on limitations of human ingenuity and computing. But, can our nascent quantum technology implement quantum cryptography securely?
The talk introduces today's quantum cryptography techniques and shows how long-distance quantum communication networks are being built all over the world, over optical fiber and satellites. I review the development of a compact quantum receiver for the Canadian quantum satellite . We have tested single-photon avalanche photodiodes under proton irradiation, and show that they can effectively be used in low Earth orbit for several years [2,3]. Then, I discuss the efforts to establish secure design and audit practices in quantum cryptography. Testing methods for several implementation loopholes and countermeasures are shown as examples [4,5]. We have recently started doing an informal security audit of new commercial systems.
 C. J. Pugh et al., “Airborne demonstration of a quantum key distribution receiver payload,” Quantum Sci. Technol. 2, 024009 (2017).
 E. Anisimova et al., “Mitigating radiation damage of single photon detectors for space applications,” EPJ Quantum Technol. 4, 10 (2017).
 J. G. Lim et al., “Laser annealing heals radiation damage in avalanche photodiodes,” EPJ Quantum Technol. 4, 11 (2017).
 S. Sajeed et al., “Security loophole in free-space quantum key distribution due to spatial-mode detector-efficiency mismatch,” Phys. Rev. A 91, 062301 (2015).
 V. Makarov et al., “Creation of backdoors in quantum communications via laser damage,” Phys. Rev. A 94, 030302 (2016).