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Transport for London plans to collect data from passengers' mobiles

news.sky.com

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Re: Transport for London plans to collect data from passengers' mobiles

#81

Post by m3rc »

ptero wrote: post #75
AliAdams wrote: post #51

That is a pretty misleading headline - this isn't asking to see their text messages or something like that; It's just tracking when and where a MAC address is seen in order to work out traffic trends. In fact some of the data looks really interesting: https://imgur.com/Hx6mDSm.jpg (credit to bcraven for the link) Most large public WiFi deploys come with this capability already included (albeit normally with an additi…

The article does seem to be blowing up a relatively small issue. However, if the intent is to work out traffic trends, it can be done much cleaner. For example, one can only track addresses within a single commute (it should not be difficult to guess from data). That is, use different hashes for the same MAC at different trips. Also, IMO any general purpose data the government collects for the public benefit that it…

100% agree. And it's unfortunate that articles like this end up being the ones discussed, it actually hurts privacy discussions by moving the conversation away from your "This data could be better anonymized and published" to "the transportation bureau is tracking your every movement".

Re: Transport for London plans to collect data from passengers' mobiles

#82

Post by Fifer82 »

victorhooi wrote: post #36
Fifer82 wrote: post #26

Earlier quoted context omitted.

So they profit, take their money, then they are not-for-profit.

You do realise this is a government body that runs public transport, right? Public transport which is notoriously bad at making profits, all around the world. Sorry, but this comes across as a bit of a silly conspiracy theory, by people who can't be bothered doing basic research.

Is not-for-profit not superflous on a government body supplying 50% of it's income? Who pays for the 6 figure board salaries? Is that from the profit part, or me the tax payer?

Just seems a bit stretched. never-gonna-profit

Re: Transport for London plans to collect data from passengers' mobiles

#83

Post by Matt3o12_ »

Sephiroth87 wrote: post #23
Matt3o12_ wrote: post #9

Earlier quoted context omitted.

As far as I know, the iPhone only randomizes its MAC address after the device has been locked for two minutes and not connected to any known networks. Two things that are very unlikely to happen in a subway. One of the advantages of riding the subway is that you can use a phone and the other one is that there is rarely any cell connection (at least in my subway), so you need WiFi anyways. WiFi randomization is great…

It's only unlikely to happen if you actively connect to the tube wifi, otherwise it works as expected, my phone will likely be locked while I get to the station, so I'll get a random MAC...

Your iPhone uses its real MAC address as soon as you unlock your device. Unfortunately, many networks still do security by MAC address, so a random MAC address would break WiFi on many networks.

Re: Transport for London plans to collect data from passengers' mobiles

#84

Post by iicc »

AliAdams wrote: post #51

That is a pretty misleading headline - this isn't asking to see their text messages or something like that; It's just tracking when and where a MAC address is seen in order to work out traffic trends. In fact some of the data looks really interesting: https://imgur.com/Hx6mDSm.jpg (credit to bcraven for the link) Most large public WiFi deploys come with this capability already included (albeit normally with an additi…

The 'sensationalism' is not at the technical detail, but TFL being opaque about their motives.

TFL's intention to "dynamically trade advertising space" is far more interesting though. Once that's in place it doesn't matter if TFL track you or not - Facebook and Google will just repurpose their existing technology, making things a step closer to the advertising in minority report.

This will likely result in a strong pressure to reduce the friction of everyone using the wifi - expect the 'paywall' to drop.

Re: Transport for London plans to collect data from passengers' mobiles

#86

Post by gsnedders »

monort wrote: post #78
matthewmacleod wrote: post #63

I'm actually happy about this. The data that has been collected is great ( http://content.tfl.gov.uk/review-tfl-wifi-pilot.pdf ) and not realistically available in any other way. The only data stored is (hashed) MAC and timestamp. It's taking place on a system where most users are already tracked semi-anonymously using contactless cards or Oyster cards, and is trivially avoidable by disabling wifi. This seems like a…

MAC do not contain enough entropy to be usefully one-way hashed. MAC address is 48 bits of which 22 bits is vendor.

The proposal, as it stands, is a salted hash, with the salt discarded once a day. If the salt isn't stored anywhere, then there's enough entropy.

Re: Transport for London plans to collect data from passengers' mobiles

#87

Post by Sephiroth87 »

Matt3o12_ wrote: post #83
Sephiroth87 wrote: post #23

Earlier quoted context omitted.

It's only unlikely to happen if you actively connect to the tube wifi, otherwise it works as expected, my phone will likely be locked while I get to the station, so I'll get a random MAC...

Your iPhone uses its real MAC address as soon as you unlock your device. Unfortunately, many networks still do security by MAC address, so a random MAC address would break WiFi on many networks.

The only source for this a could find was an old paper on iOS 8, while this more recent one https://arxiv.org/pdf/1703.02874.pdf seems to suggest the randomisation works as intended for unknown networks...

Re: Transport for London plans to collect data from passengers' mobiles

#88

Post by tobylane »

Fifer82 wrote: post #82
victorhooi wrote: post #36

Earlier quoted context omitted.

You do realise this is a government body that runs public transport, right? Public transport which is notoriously bad at making profits, all around the world. Sorry, but this comes across as a bit of a silly conspiracy theory, by people who can't be bothered doing basic research.

Is not-for-profit not superflous on a government body supplying 50% of it's income? Who pays for the 6 figure board salaries? Is that from the profit part, or me the tax payer? Just seems a bit stretched. never-gonna-profit

For-profit also doesn't fit well in an organisation running a bus network that spends £1.5b a year more than it takes in.

Re: Transport for London plans to collect data from passengers' mobiles

#89

Post by criddell »

benbristow wrote: post #73
criddell wrote: post #64

Earlier quoted context omitted.

Don't Android and iOS randomize the MAC addr these days? Are they investing in something that's going to have a very short life?

You need to login to the TFL WiFi using your Virgin Media or supported phone network's login, so they can identify you by that instead.

Is that just if you want signal under ground, or is having WiFi turned on a requirement for riding Tfl?

Re: Transport for London plans to collect data from passengers' mobiles

#90

Post by ballenf »

AliAdams wrote: post #51

That is a pretty misleading headline - this isn't asking to see their text messages or something like that; It's just tracking when and where a MAC address is seen in order to work out traffic trends. In fact some of the data looks really interesting: https://imgur.com/Hx6mDSm.jpg (credit to bcraven for the link) Most large public WiFi deploys come with this capability already included (albeit normally with an additi…

I understood them to offer wifi service and track its use, but maybe I was reading too much into it.

The revenue was discussed as coming from targeted advertising implying tracking of data usage.

I'm skeptical for a different reason: all they're going to see is a bunch of connections to facebook servers which will all look alike. /s

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