On 01.09.2017 3:39 PM, Neil Williams wrote:
On 2017-09-01 12:23:05 +0000, John Levine said:

There's a reason that transit systems increasingly use proof of
payment rather than gates.

Er, do they? European countries seem increasingly to be adding gates
to allow CPCs to be used.

It's only a matter of time before a CPC authorisation will be possible
in a fraction of a second.

Here in Buc we now (finally) have Contactless on all the Metrou gates (until
this year it was one or two of the old gates at each station with a
somewhat botched-on card reader, but now all the gatelines seem to have
been replaced with shiny new ones.) On the other hand, they replace (well,
supplement really) the old-school cardboard carnet style tickets with a
little dot-matrix printer that prints your remaining journeys on the ticket
each time you check in (in case anyone thinks this is uniquely backward,
I'm pretty sure NY had the same type last time I was there, although it was
a while ago), so contactless is no slower. The sort of throughputs that
(say) Victoria tube station requires are not the norm internationally.

Anyway, this still doesn't assume it's pay-later. In Bucharest the
communications infrastructure is top notch (my home broadband is 350Mb/s
actual achieved speed for 10eur/month - I could have 1Gb/s for about two
euro more) so all card transactions are authorised online. That's one
reason we have no limit for contactless transactions. (Here we implement
the Contactless+PIN part of the EMV standard that the UK ignores, because
the PIN is always validated online and not by the card chip.)