Hi, 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 Indonesia 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. Cheers Justin