QEYSSat moving forward

Some context:

I've been involved with the QEYSSat project, working on studies and prototypes, for the last 6 years. It's wonderful to see it selected as one of the two projects to receive funding, thereby allowing it to become an actual mission. Very exciting times!

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Our airborne QKD trials were mentioned in The Globe and Mail

September of 2016 was a busy month for a few reasons, one of these being the two weeks I was (with the rest of our IQC team) in Smiths Falls outside Ottawa conducting trials of our prototype quantum key distribution system. Ultimately this involved transmitting quantum signals from our ground-station quantum source to our receiver on a flying NRC aircraft—quite successfully, I might add. In the intervening time to now (and modulo one vacation to Australia and New Zealand) we wrote-up our results into a paper, the pre-print of which recently appeared on the arXiv.

At the same time (not coincidentally) an article about our work appeared in the Canadian newspaper The Globe and Mail—page 1 on Dec. 21, in our region—as well as the Waterloo Region Record (pg. 2, Dec. 22). You can read the online edition of the article.

So that's neat.

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How to update Debian KDE packages to unstable

I use Debian with KDE's Plasma desktop environment. I usually track Debian's testing repository, but often I like to upgrade the version of KDE packages installed to more recent versions in the unstable repository. My preferred way:

sudo aptitude --visual-preview -t unstable install ~i~mkde

The action tends to be independent of anything else, but that's easy enough to work around—update per usual before running.

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Using Unison with Android over USB

For some time, I've been happily using Unison in conjunction with my Android phone's USB mass storage function to synchronize files between my phone and my desktop. It was simple: I'd plug in my phone with USB and enable the SD card to be used as a mass storage device, then mount it in Linux and run Unison as if the phone was a local folder (with appropriate tweaks to support the FAT filesystem).

Alas, my phone was getting on in years (or months, as it is in tech), and with support long dropped and capacity nigh exhausted, I had to upgrade. With my new phone I've been promoted to the “new hotness” that is Android 6 Marshmallow, but one of the functions that was dropped along the way was the ability to expose the SD card as mass storage over USB. Admittedly it wasn't a perfect solution, requiring unmounting the SD card within Android itself while using it over USB, but the current approaches introduce their own deficiencies. In any case, my previous workflow wasn't going to work anymore.

Of course I didn't want to stop using Unison, or have Unison re-copy everything, or even merely re-scan everything. I [...]

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Published in Optics Express: Free-space quantum key distribution to a moving receiver

We take our quantum key distribution system out of the laboratory and mount it in the back of a small truck. Integrating a two-axis pointing system at both sites, polarization correction, and time-of-flight compensation, we demonstrate quantum key distribution from a stationary transmitter to a receiver moving at an angular speed (relative to the transmitter) equivalent to the maximum angular speed of a typical low-Earth-orbit satellite.

J.-P. Bourgoin, B. L. Higgins, N. Gigov, C. Holloway, C. J. Pugh, S. Kaiser, M. Cranmer, and T. Jennewein
Optics Express 23, 33437–47 (2015)

Bonus: Read the IQC's news release, which covers both this and the previous paper for a general audience.

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Published in Physical Review A: Experimental quantum key distribution with simulated ground-to-satellite photon losses and processing limitations

Fundamental laws of quantum physics guarantee the security of encryption keys generated through quantum key distribution, in contrast to standard encryption techniques which rely on assumptions about an eavesdropper's computational ability. That said, special technology is necessary to facilitate quantum key distribution transmissions between parties that are more than a couple of hundred kilometers apart.

A near-term solution is to use an orbiting satellite as a trusted quantum receiver. Here we detail specifically chosen algorithms that make up an implementation of quantum key distribution, suitable for a satellite receiver platform. We examine these algorithms' computational requirements while demonstrating them experimentally as we emulate the variable channel losses that would be experienced during a satellite pass (following those we published about previously).

J.-P. Bourgoin, N. Gigov, B. L. Higgins, Z. Yan, E. Meyer-Scott, A. K. Khandani, N. Lütkenhaus, and T. Jennewein
Phys. Rev. A 92, 052339 (2015)

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