I participated in the powers of tau ceremony. This was a fun one, not as cool 
as radioactive material but I leave the judgment to the reader ;-)

Farraday cage used: Airbus A320 ;-)
Country of calculation: technically „none“ for a good amount of time, then 
Long story short: Calculation done on airplaine tray table on an unexpteced one 
day later flight and on a homestay on Bali.

So here is some background: My MacBook Air (Sierra 10.12.6) was always with me 
and always destroys the filevault encryption keys after being in standbye for 
more than a couple of minutes. I have been traveling for the last 10 1/2 months 
around this globe, have been to South Africa, South America (Brasil, Argentina, 
Bolivia, Peru, Ecuador, Colombia), a little bit of central america (Panama, 
Costa Rica), north america (Mexico City), Hawaii, New zZealand (3 1/2 months). 
So you can say that either every national intelligence agency had chances to 
have a look or none because me myself often/usually would only know 1-3 days in 
advance where I would be in 1 to 3 days. (all travels usually youth hostels or 
nice host families)

I have been in Australia the last 3 weeks. So I prepared the software setup 
from a hostel in Cairns. I was then supposed (!) to be on the flight to Bali, 
but was at the end of the luggage check-in queue and the flight had a passenger 
cap for safety reasons. I originally planned to do the calculation on the 
plane, so any adversary trying to follow me probably ended up sitting on the 
first plane and would have had to organise a ticket for the flight the 
following day. I did download the challenge file over the hotel wifi (I got 
provided accommodation by the airline). Worked out nicely because Sean provided 
me with the files just in time for the second, initially not expected flight. 

I then boarded the flight, waited for the start and then used my physical dice 
that I packed with me to get some random numbers. I also used a combination of 
dice rolling to define some seconds and then count the number of clouds I could 
see from ym window seat. I also counted the number of different colour 
boundaries I could see in the sunset with the clouds. I meshed this numbers 
into various text input fields of my system (wifi and bluetooth were disabled).

I then started the calculation using the Go implementation. I forgot that my 
laptop would go into sleepmode so it went into sleep mode and into deep sleep, 
but continued the calculation (might mean that a sleepimage might have been 
written to disk, more on that later).

The calculation went on, at some point my laptop ran out of power. I never left 
it unattended (I took it with me to the toilet!). I landed in Bali with the 
empty battery, went to my stay after many tens of minutes of driving through 
nightly Denpasar and then continued the computation from the room. The laptop 
was then ~20cm away from my bed (but I went to sleep and set myself an alarm 
clock). I woke up in the night (room was key locked from within with key in the 
door and windows have steel bars). I rebooted the computer and uploaded the 
response file.

Oddities that I noticed:

When setting up and playing around with my laptop in Cairns in the hostel, I 
used my Bluetooth magic mouse (so bluetooth was enabled). Out of nowhere, I saw 
a connection request from someone’s LG phone that popped up (that I declined). 
This happened two more times in short succinction before I disabled Bluetooth 
(might have been a person at the pool outside my window). What I don’t 
understand is why my Macbook would be visible in Bluetooth (I checked 
preferences, it shouldn’t have been visible).

The other odity that I observed (and can’t remember having seen in a very very 
very long time) is my complete Bluetooth stack being „rerecognised“ à la 
„unplugged and replugged USB device while sitting in the airport. I noticed 
that through HardwareGrowler which shows me changes of the hardware that my 
Macbook is aware of).

How I destroyed the toxic waste:

I rebooted my machine and as this machine is every 1-3 days complaining about 
having too little disk space left, and me shuffling big files around very 
often, the likelyhood of remnants staying on the ssd and not being overwritten 
soon are very small. Encryption keys to my SSD are destroyed after some time in 
standby, so obtaining them access to the SSD is rather hard. I did duplicate 
some files to fill up my hard disk space so, anything that was there is almost 
certain to have been overwritten at some point.

If there are any further questions, feel free to reach out.


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