New Bluetooth tracking signals in Ireland

brianhere · 23-09-2021 3:48pm #1

First of all a short recap on what we mean by Bluetooth. In order to replace physical wires, in the late 80s/90s it was thought convenient to communicate between electronic devices using a wireless protocol, and so then such a protocol was developed in the Ericsson company in Sweden and became effectively the world standard for such short range communication. It uses 2.4 GHz radio frequencies and is familiar with most computer users as a short range system for things like headphones, car mobile hands free systems, watches that feed off a main mobile phone, etc, and is now built into many of the chips used in a vast array of electronic devices.

That is classic Bluetooth, as it were, but in December 2009 for Bluetooth version 4.0 they expanded their protocol to encompass a completely different system originally developed by Nokia. In this you have a 'central' computer - say your mobile - reading data transmitted as 'advertisements' from a 'peripheral' beacon, which is a low energy transmitter of data. The 'beacon' could be very small and could last a long time even on a small battery because the protocol only involves transmitting a few bytes of data periodically. In particular it transmits at least its UUID number, possibly the brand and model of the device, and the strength of the signal as received 1 metre from the device (txPower) (this is then used in combination with the strength of the signal as received by the central computer (RSSI) to give an approximate distance from the two devices).

This is called Bluetooth Low Energy (BLE) and could involve much longer distances than regular Bluetooth (750 metres was mentioned as a possibility, but of course it all depends on the power of the transmitter) and was flavour of the month in computer networks for a few years after it came out. Soon big tech rolled in with their own subsets of the general protocol, including Apple who brought out iBeacon in 2013, and Google who developed Eddystone in 2015. And after that it mostly went away, with both companies above closing down or limiting their offerings in this field. Until now, with Covid.

The protocols and stacks developed by Apple and Android to assist contact tracing, and then used by national health authorities in their various apps, is this resurrected Bluetooth Low Energy system. So hence an Apple device say, will now broadcast (possibly constantly, or maybe only when the screen is lit) this low energy beacon which can be picked up by a neighbouring mobile which can then record that UUID and hence if the owner of the Apple mobile was later deemed Covid positive they have a list of other mobiles that he/she was in contact with i.e. the UUID numbers transmitted by the Low Energy system. (Incidentally these UUID numbers are considered unique because they are random numbers generated from a gigantic set of possible numbers, not because they are ticked off in some central database. Also sometimes the numbers have a relationship with MAC addresses - the MAC address being part of the larger UUID number -, which are in a central database, and hence can be unique that way. This Mac concatenation does not seem to be true of these Covid UUIDs though, because Apple etc change the numbers every 10-20 minutes, in order to prevent tracking of the mobiles.)

So ok, what does all that mean and why should we be concerned? Because now virtually every electronic device you have seems to be broadcasting these signals and yes you can be tracked by them. As an experiment try and download the nRF Connect app from Nordic Semiconductor on Android (and the company also have an iPhone app), go to some public place watching people come and go and marvel at the details you can pick up about them. Apple and Garmin watches, dashcams, smart TVs, Windows 10 computers and obviously mobile phones will pop in and out of your screen to an extraordinary degree.

Covid has demolished privacy it seems!

ohnonotgmail · 23-09-2021 4:00pm

what does this technology have to do with covid?

brianhere · 23-09-2021 4:44pm

I think before Covid you would hardly find these signals anywhere, Bluetooth Low Energy was not widely supported, now, because of the Covid tracing apps, its everywhere.

banie01 · 23-09-2021 5:04pm

https://www.boards.ie/discussion/comment/117930055#Comment_117930055

You are ascribing the adoption of BLE to Covid?

I have a bit of experience regarding the use of BLE geo fencing and it's been in widespread use for over 10yrs.

Both for targeted/localised adverts and in its more usual use for connecting wireless accessories to each other.

Do you have the same concerns regarding your phone's WiFi, GPS and Mobile connection? All over the same degree of traceability, albeit at a higher power drain.

All EM signals can be captured and traced. Bluetooth LE is used to connect personal devices and to act as a beacon/contact indicator. Using it in that manner is a choice, if one wishes to disable the exposure notifications? Just disable it, either in the app or via just switching it off. The actual retention of device exposure data on BLE is in any case retained on the phone and only uploaded by consent IIRC? And even at that, the meta data ID generated is random and only matches another user when they also upload their data by consent and there is a reconcilation time stamp match.

I get that you have privacy concerns, but your interpolation of BLE with Covid just seems a bit of a stretch IMO.