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The tiny chip that powers Montreal subway tickets

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Re: The tiny chip that powers Montreal subway tickets

#111

Post by cypherpunks01 »

jeffbee wrote: post #11
cypherpunks01 wrote: post #8

Earlier quoted context omitted.

Most people who live in Boston use the reloadable CharlieCard ( https://www.mbta.com/fares/charliecard ) - these report as Mifare Classic 1k, which is a similar chip There are single-use fares as well, the "CharlieTicket" that you might've encountered. More CharlieCard NFC info: https://medium.com/@bobbyrsec/operation-charlie-hacking-the-... https://media.defcon.org/DEF%20CON%2031/DEF%20CON%2031%20pre...

Yeah I figured but you can't buy a charliecard online to load into your smartphone wallet, and I only needed it the once, and since it took more than an hour to get to Cambridge due to some combination of circus acts I used Blue bikes for the remainder of the day.

Ah yes, it's not quite there, but almost. Contactless payment directly at the turnstile is coming to Boston MBTA this year, I believe. Like how NYC works now, where you can just use your credit card for entry.

Re: The tiny chip that powers Montreal subway tickets

#112

Post by Tijdreiziger »

1oooqooq wrote: post #94
thriftwy wrote: post #50

Earlier quoted context omitted.

For a few years now, you may usually do a contactless card payment - just tap your bank (debit or credit) card. The fare is often higher but so is convenience. Back around 2010 I remember reading these accusations that significant part of revenue went directly to Mifare for the massive number of chips. And for single rides, some of Metro systems still use these steampunk brass tokens. Sometimes, less authentic plasti…

every single transportation system that uses disposable nfc are definitely making a ton of money for the vendor. and every transportation system that pretends to run as a profit center and not a cost center also makes ton of money for the vendors.

In the systems I’ve ridden, there’s usually some kind of plastic stored-value card for regular riders, and the (more expensive) disposable tickets are only used by occasional riders.

Re: The tiny chip that powers Montreal subway tickets

#113

Post by seizethecheese »

kens wrote: post #2

Author here for all your NFC chip questions :-)

I’ve been curious about the orientation of these devices. For examples, if I want to track an item’s presence in a box, would I have to coat the entire item in these chips to get one to be in the right orientation?

Re: The tiny chip that powers Montreal subway tickets

#114

Post by rendx »

Sytten wrote: post #108

They are going away soon (TM), the tech is cool but they are impractical. I will be happy to use my credit card or phone. Too many times I have been stuck in 15-20 minutes queues to buy those tickets and you cant refill them with an app... Plus south shore and north shore have they own system it's a mess.

I dread the privacy implications. No thanks.

Re: The tiny chip that powers Montreal subway tickets

#115

Post by kens »

ak217 wrote: post #96
kens wrote: post #2

Author here for all your NFC chip questions :-)

Thanks for the write-up. How does this fit into the broader NFC ecosystem? What do other big metro systems like Omny, Clipper, Smartrip etc use? Apple and Google seem to implement some NFC protocols in their devices but in a much more programmable way, how does that work? Is the protocol used in credit cards related at all? And how do these relate to Felica, the system used everywhere in Japan (which was in the news…

That seems like a question for @lxgr :-)

As far as I can tell, the NFC ecosystem is a mess of competing, incompatible protocols from different companies, as well as incompatibilities for historical reasons. For example, Clipper uses MIFARE DESFire, which is the more secure sibling of the Ultralight chip that I examined. Washington's SmarTrip cards use MIFARE Plux X. New York City's OMNY, on the other hand, is apparently built on top of the Mastercard payment network using EMV. Montreal's rechargeable OPUS card (not the disposable one I examined) uses the completely different Calypso standard. FeliCa was developed in Japan along a different path and has a different standard (NFC-F vs NFC-A) with different modulation, protocol, and data rates. The NFC chips used in phones try to be compatible with as much as possible. These NFC systems all use the same 13.56 MHz frequency, so the radio hardware is compatible across them.

Re: The tiny chip that powers Montreal subway tickets

#116

Post by vhcr »

rendx wrote: post #114
Sytten wrote: post #108

They are going away soon (TM), the tech is cool but they are impractical. I will be happy to use my credit card or phone. Too many times I have been stuck in 15-20 minutes queues to buy those tickets and you cant refill them with an app... Plus south shore and north shore have they own system it's a mess.

I dread the privacy implications. No thanks.

No need to worry about privacy, facial recognition already takes care of that.

Re: The tiny chip that powers Montreal subway tickets

#118

Post by kens »

seizethecheese wrote: post #113
kens wrote: post #2

Author here for all your NFC chip questions :-)

I’ve been curious about the orientation of these devices. For examples, if I want to track an item’s presence in a box, would I have to coat the entire item in these chips to get one to be in the right orientation?

I think it depends on the type of antenna. A linearly polarized RFID antenna is sensitive to the tag's orientation, but a circularly polarized antenna is less sensitive to orientation. Systems can also use more than one RFID antenna to get better coverage.

Re: The tiny chip that powers Montreal subway tickets

#120

Post by kens »

maaarghk wrote: post #117
kens wrote: post #2

Author here for all your NFC chip questions :-)

Not an NFC chip question, but what kind of microscope do you need to get silicon photos of a chip so tiny?

The trick is to use a metallurgical microscope, which shines the light down through the lens. A regular microscope illuminates from below, which works fine for cells, but not for opaque chips.

Specifically, I use an AmScope ME300TZB-2L-10M microscope, which my friends consider an entry-level microscope, but it works for my needs.

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