Submitted for the enjoyment of the Zapps Working Group, we present the
Powers of Tau 41 video report:

On Mon, Jan 22, 2018 at 2:53 PM, Andrew Miller <> wrote:

> Dear Zapps-WG,
>   Please see below for our writeup about the first *airborne* Powers of
> Tau, using  a *radioactive artifact from Chernobyl* as the entropy source.
> Thanks to Ryan for the exciting take on "toxic waste" and the dedication to
> follow through with this all! I recorded a lot of selfie vlogger go-pro
> footage of our trip so I'll upload a youtube video as soon as I'm done
> editing it all up.
> Cheers,
> Hash: SHA1
> Powers of Tau Operational writeup
> =================================
> Round: 41
> Principals: Ryan Pierce and Andrew Miller
> Date: 2018-01-20
> Location: North Illinois and Southern Wisconsin
> Altitude: 3,000' AMSL / approx. 2200' AGL
> Commit version: 9e1553c437183540392a7231d0788318a19b18a3
> SHA256 of ./compute: 922b2e0a59841ecdaba7b4953d8c67
> e62b74b8f52f968624cff664dc086da93a
> SHA256 of challenge file: c48fbf0a267ea9a9596c09aaf91f6a
> cc18b48430e9239c18de583055b32d503d
> blake2sum of response:
>     8a5a9bcb a9c3ab76 c7e3a881 2ccd01e6
>     9af2153b 5d0f9668 9f790493 37de1fb3
>     28873f5f 771adef1 adf0486e 4904b28d
>     96fe602c 8866f42e 8047ce3b dafe2f9e
>     73c7d2cd 1b0c023d 3831a462 42bd6fc9
> Preparation steps
> =================
> As we know, Powers of Tau is all about generating and safely disposing
> of cryptographic "toxic waste." So, what better way to generate
> entropy than with actual radioactive toxic waste?
> For our contribution, the entropy source was a hardware-based random
> number generator utilizing a Geiger tube and a radioactive source,
> constructed and programmed by Ryan Pierce. It was based off of the
> MightyOhm Geiger Counter kit, available for purchase at
> The radioactive source chosen was a very small, low activity sample of
> the graphite moderator ejected from the core of the Chernobyl Unit 4
> nuclear reactor during the 1986 explosion and meltdown. The primary
> activity of the source comes from the fission products Cs-137 (a gamma
> and beta emitter) and Sr-90 (a beta emitter.) Gamma activity at the
> surface of the sample container was approx. 0.7 uSv/h, falling
> substantially below all thresholds that might restrict its
> transportation by air, and posing no health risk. This dose rate is
> only a few times the dose rate of normal background radiation.
> The specific Geiger tube used was a Soviet SI-22G that was recovered
> from the Chernobyl Exclusion Zone. This tube is sensitive to gamma and
> hard beta radiation.
> Ryan re-wrote the firmware for the kit's ATtiny2313 AVR
> microcontroller to act as a random number generator, using the
> difference in timing between consecutive pairs of Geiger tube pulses,
> measured in microseconds. The idea for this method came from John
> Walker, who implemented this in 1996.  See
> Ryan's source code is available at
> To sanity check the output of the generator, we ran a standard battery
> of statistical tests, all of which passed:
>     dieharder -a -k2 -Y 1 -f geigersamples.input >
>     geigersamples.output
> The Geiger input and output files are available via github, above. For
> information on dieharder, see
> The code is configured to output a stream of 64 bytes of random
> entropy, expressed as 128 hex characters, followed by a CRLF, when a
> user presses a button on the Geiger counter RNG. The interface is a 6
> pin FTDI header, and it transmits TTL serial data at 9600 baud. A
> standard FTDI USB cable connects the Geiger counter RNG to the
> laptop. The serial TTY was configured as follows:
>     stty -F /dev/ttyUSB0 9600 raw
> Pressing the button caused 64 bytes of entropy to be entered into the
> computation program, without displaying it to the laptop screen, using
> the following command:
>     head -c 128 /dev/ttyUSB0 | ./compute
> A picture of the RNG, tube, and source can be seen at
> Side channel defenses
> =====================
> Andrew procured a laptop to serve as the compute node, purchased from
> a randomly chosen 1 out 4 nearby Walmarts and/or Best Buys. The laptop
> purchased was an HP Jaguar 15‑bs060wm, with 8GB of RAM and an Intel
> i3-7100U processor (2.4 GHz, 2 cores). The laptop was booted from a
> USB drive with Ubuntu 16.04. The hard drives and wifi were disabled in
> software, but were *not* removed due to the difficulty in unscrewing
> the laptop.
> To reduce the risk of side channel attacks, we performed our
> contribution to the ceremony while airborne in Ryan's Piper
> Cherokee. Ryan and Andrew were the only occupants in the aircraft. No
> mobile phones were powered on during the flight. The only mobile
> device in use was an iPad 2, with cellular and WiFi disabled but
> Bluetooth and GPS enabled, running ForeFlight electronic flight bag
> software. We departed on a VFR flight from Waukegan airport (KUGN),
> located in Illinois, near the Wisconsin border. Once we reached 3,000
> feet AMSL, Ryan performed a 360 degree steep turn to assure ourselves
> that no aircraft or drones were following us. We set up the Geiger
> counter RNG and laptop and began the computation. During this time, we
> made occasional random turns, flying over northern Illinois and
> southern Wisconsin while remaining outside the O'Hare Class B
> airspace, until the compute finished. We observed no suspicious
> aircraft attempting to follow us. The total compute time took around
> 30 minutes. We then flew to Schaumburg Airport (06C) where we uploaded
> the response file at Pilot Pete's restaurant. We made a return flight
> to Waukegan later that afternoon.
> Pictures from the trip:
> We’re also currently producing a short video about our trip, which we
> plan to publish to Youtube and notify the zapps-wg mailing list.
> Version: GnuPG v1
> Ll5G+X9+Kjrhq0RYXmjix50pEgkpEZhTzKnPxo4tNiiaRc34waKpCAFZpn2Yfpq5
> 8o3R3rTDjYlGcMVyWciipUvbtzxfxrs5GRXknTGhtLvhljZM+fq09O4raPn+oj5Y
> tDiFKAO0tKx5wXqlg8diM5AxUfveX6Kov0844ctV+7rP6OYOgCEjqD/o/vM0kVUR
> R5wvh7dqY2VHvh7LYAjUSOwbQ4M+3LCw9fK0dAZrXqT9Yn5DquGYKj39QsHJoJ9R
> 4uoDb6ltPJuZDCJ0wBKHiyfMr3++UKTDj6dRkHF2OD7aBk4jPZUC6YCC5zgQFPxL
> MrBv137EBijmtu4uFfT2YM7SJkKa+AGXnhzsIdFKy5U4Ahqa7meA9sDdAHdOgR9W
> RVq9wuO3OnL12Oj53N/PEVtxgmWxHVZfIKP5EPihhSklWC6RU8XVgV4OlfGkkYkA
> YyrYNGjSTDI6YXVNXl4uKttzVg965tSt5+83HhuEFepR3+HFgmXz+suYa53J8rxX
> njESFI0qV7j7VzLnwthAjV5u0ZAY0y9vOTnMB1nLwVZEKl/g3/WNZhDes9xuyYqV
> fAXjVfM2YQ2mQui9U60g0XfSgnO/tnLVG8Fsiv3Jy2yx5baZect8nl3wX6qyWAiM
> d/vM2xKNhdf49qfltNQn
> =rmAp
> On Sat, Jan 20, 2018 at 12:08 PM, Miller, Andrew via zapps-wg <
>> wrote:
>> Here's our response, should be done uploading to s3 in a moment.
>> 9af2153b5d0f96689f79049337de1fb328873f5f771adef1adf0486e4904
>> b28d96fe602c8866f42e8047ce3bdafe2f9e73c7d2cd1b0c023d3831a46242bd6fc9
>> Long story short:
>> - Contributor: Ryan Pierce and Andrew Miller
>> - Isolation: 3,000 feet above ground in a Piper Cherokee
>> - Entropy source: geiger counter and a Chernobyl reactor graphite sample
>> Entertaining writeup and video to follow! (Note: all appropriate aviation
>> and radiation regulations were followed to a tee)
>> --
>> Andrew Miller
>> University of Illinois at Urbana-Champaign
>> ________________________________________
>> From: Sean Bowe []
>> Sent: Wednesday, January 17, 2018 10:22 PM
>> To: Miller, Andrew
>> Cc: Zapps wg
>> Subject: Re: [zapps-wg] Powers of Tau
>> It does interfere with someone, but we could make it work Saturday
>> morning if you don't expect it to take longer than the morning.
>> Sean
>> On Wed, Jan 17, 2018 at 9:18 PM, Andrew Miller via zapps-wg
>> <> wrote:
>> > Greetings everyone,
>> >    I have a good one planned. But it's got a difficult time constraint.
>> I
>> > need to go this coming Saturday morning. Hopefully it won't interfere
>> with
>> > the batting order much if I ask for priority! Thanks,
> --
> Andrew Miller
> University of Illinois at Urbana-Champaign

Andrew Miller
University of Illinois at Urbana-Champaign

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