In message , at 15:50:47 on
Fri, 1 Nov 2013, Paul Corfield remarked:
Proof of payment does not exist
if the ability to reveal it depends on the integrity of the party demanding
the proof.

It's as though I bought something in a shop and, when asking for my receipt
to ensure there are no problem passing the security guard on the exit, am
told I don't need one because the shop has all the evidence it needs to
satisfy itself that I paid for the goods.

There's also a parallel with the move from signing credit card
authorisations to chip-and-pin.

We are being coerced into having to trust potential adversaries.

Any yet millions and millions of transactions are conducted daily in
London using Oyster with minimal problems. Are you seriously
suggesting that hundreds of miles of paper transaction slips should be
created for no real purpose? How do you deal with ticket gates on
railway stations? Remove them? fit printers and require peo

I think there's clearly some merit in both points of view.

Obviously no-one is going to start issuing bits of paper to confirm
Smartcard transactions because going e-ticket/e-cash is the whole point
of introducing them.

But there's a genuine concern that transactions become *much* harder to
audit from the consumer's point of view, and a lot of the time it's a
case of "trust us, we have the computer".

Oyster have in fact been improving the auditability over the years, and
it's now reached a state that I think most people will be happy with.
It's even possible to produce records that a finance department will
accept for the purposes of claiming expenses. What a novelty!

I hope that ITSO cards will *start* with that level of user
auditability, but I've yet to see it in practice.

From a convenience point of view, I very much like the Nottingham bus
smartcard carnet system, but it's almost entirely unauditable. All the
passenger gets is a quick flash of the number of days left, when it's
first used each day; or you can visit one office in the City Centre and
think they'll give you a verbal quote.

I think a lot of the problems arise because the systems are really
designed for season tickets, where (as you've described regarding your
own usage) it doesn't really matter [to anyone] if you swipe zero, one
or two times. And trying to apply the same processes to PAYG use, where
suddenly it does matter.
--
Roland Perry