Shostack + Friends Blog Archive


London’s New Transit Card

transport for London.jpg

Transport for London is trying to get as many people as possible to use Oyster Cards. They are cheaper — and theoretically easier to use — than traditional tube / bus tickets. However, using one means that TfL has a record of your journeys on the transport system, which is something that not everybody is comfortable with.

Photo: Voyeur by Jeff VC

4 comments on "London’s New Transit Card"

  • Actually, they have a record of the card’s journeys on the transport system. You can buy them and recharge them with cash and swap them with friends and family, etc.. There is no link to your personally other than the surveillance cameras and payment card, if you happen to use one.

  • the-not-so-invisible-man says:

    Oh, so what you mean is “There is no link to you personally” as long as you are invisible and always top up using cash..
    Great. ~:/

  • NIcko says:

    Now that the encryption is broken on the MiFare card technology it seems to me that someone needs to set up a service which allows you to swap your Oyster card with someone you don’t know who’s card has about the same value remaining, on line, without ever meeting the other party. As long as the operators of the service didn’t (or cryptographically couldn’t) collude with TfL you could pretty completely break the linkability of the system.

  • @ not-so-invisible
    yes, that’s what i mean. the invisible part is hard but not impossible. the cash part is easy, but you lose many of the discounts.
    @ nicko
    doesn’t need to be broken to do this. you can swap all you want today.
    bottom line is that the people who can pay, can remain anonymous. this usually means the people passing-through on a short-term. the ones who are most likely to be tracked/identified in conjunction with oyster are those who want reduced/subsidized long-term fares.
    this is a trade-off, and can even be argued as a reverse tax system, that has more to do with economics of public transit and fare management than security. they need some kind of id to prove you deserve a child fare, for example. if you do not want to link your child’s face to their pass, and enable tracking on the transit system, then pay cash for a full card.
    it’s not a lot different from the convenience/loyalty systems in retail. you get a price-break in exchange for giving identity information. if you see your identity as more valuable than the discount, then don’t given in.

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