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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

#411

Post by vaughnegut »

reportgunner wrote: post #387

I was living under the impression that the Oyster card already solved this problem years ago.

iirc (it's been over a decade), the Oyster card is a plastic card with an NFC in it. Montreal's Opus card does the exact same thing (and is probably modelled off of it and similar implementations in other cities). This article is describing the disposable, single-use ones.

If you don't want to use disposable ones, the same kiosk that dispenses the temporary cards will allow you to buy a permanent one which you can load with fares as normal.

Re: The tiny chip that powers Montreal subway tickets

#412

Post by lxgr »

kumarvvr wrote: post #287
lxgr wrote: post #258

Earlier quoted context omitted.

I find the plastic tokens quite clever, but QR codes are not a great option for mobile ticketing at transit gates: Often it takes people forever to pull up the code in the right orientation and dial up the brightness enough for the scan to work. Not something I love to deal with when I want to catch a train.

QR code reading does not depend on the orientation, at-least as per its spec. there are many apps and devices out there that can read a QR code in any orientation. In the app that is used by me, the brightness of the screen is automatically increased by the app as soon as I open the ticket QR, and then reduces to its previous state, once the QR code display is removed.

Not any orientation – if you present a QR code ticket the wrong way around, or even just angled away from the plane the reader focuses on too much, it doesn't work.

Contactless tickets work both ways, and in addition to that usually have a larger, more forgiving "landing area". On top of that, they can usually read through a wallet (but that's more relevant to regular commuters, arguably; tourists and infrequent riders will likely have purchased the ticket just moments before using it).

Re: The tiny chip that powers Montreal subway tickets

#413

Post by Piskvorrr »

BiteCode_dev wrote: post #401
fennecfoxy wrote: post #362

Earlier quoted context omitted.

Touch x against y versus line this weird printed shape up at just the right angle in good lighting conditions. I feel like NFC is much easier to tell older folks how to use as well. I'm all for the "we have technology why tf don't we use it, why aren't we better at it" argument, but the truth is that a lot of tech/systems in transport & other areas are retro af and new stuff gets shoe-horned in with all the caveats o…

> weird printed shape up at just the right angle in good lighting conditions None of that matter. QR code can be read on any angle because of the 3 position detection patterns it comes with, by design. Lighting conditions are not a problem on tickets (which is what the article is about) because you can illuminate the paper from the camera. QRCode were fast on assembly lines two decades ago. They were invented in the…

Actually, they do matter.

Assembly lines give you GREAT control over where the code is located, how it's lit (consistently), and what you do on read error (can't shunt off the passenger to a read error bin, so they don't hold up the line). Rotational angle doesn't matter, perspective skew does. And then - it's a leaf of paper, so you get folds and obscured parts (yes, correctable...up to a point).

Re: The tiny chip that powers Montreal subway tickets

#414

Post by exitb »

bluGill wrote: post #389
joenot443 wrote: post #365

Earlier quoted context omitted.

Most North American cities sadly don’t operate at the level of trust required for a system like that to work, as much as I agree it would be better for everyone.

Many cities in North America do. The key is the fine for not having a ticket is high enough that you are on average much better off having a ticket. Generally this works out to enough random inspections that the average person is checked once a month, and the fine for not having a ticket works out to the cost of a 3 month pass. The exact numbers are of course subject to debate, but the above should give any city a go…

Where I live, I'd be far better off not buying the tickets. The fine is less than 2 months with a pass and I'm checked 2-3 times a year. Yet most of these checks don't find anyone without a ticket. Monthly ticket costs about 1.5% of average monthly income for that city, less than 4% of minimal wage. I'm quite convinced that reasonable pricing is the key.

Re: The tiny chip that powers Montreal subway tickets

#415

Post by lxgr »

zulban wrote: post #397
lxgr wrote: post #257

Earlier quoted context omitted.

> If waste bothers you, focus on something worthwhile like canceling just one airline flight. That's just whataboutism: If there's an alternative way of solving the same problem that generates less waste, why not use it? I find the contactless coin form factor for single rides quite clever personally, and I don't see any downsides compared to paper single-use tickets (other than that validators and gates need some st…

Just because you don't see downsides doesn't mean there aren't any. Coins are lost or broken or intentionally damaged, and may need cleaning and staff to handle and transport them. It's not zero waste. In fact I suspect the STM solution may overall have less waste. If you read the article, the chip is the size of a grain of salt. Airline is not just whataboutism. It illustrates the absurdity of scale in your point. I…

> I suspect the STM solution may overall have less waste. If you read the article, the chip is the size of a grain of salt.

The antenna isn't, however. In any case, I think there's a pretty high chance these tickets will not end up in a dedicated recycling facility that can properly separate antenna from paper and recycle both, disregarding the chip.

For similar reasons, Japan is phasing out even magnetic stripe single-ride tickets out of recycling concerns (in favor of QR code based ones).

> Imagine someone who is spending 20 minutes to save themselves 4 pennies on their electrical bill

That's not an appropriate comparison, though. Buying a reusable token doesn't take 20 minutes more than buying a paper ticket.

Imagine instead a device manufacturer spending some months of R&D to help every single household in a large country save 4 pennies on their electrical bills, and it doesn't seem so absurd anymore.

Re: The tiny chip that powers Montreal subway tickets

#416

Post by amluto »

m463 wrote: post #273
amluto wrote: post #32

> Presumably, the makers thought that making the card look like a smart card would help people understand it. The card actually uses an entirely different technology. It’s kind of the same, though. The physical communication layer is different, but the higher protocol layers are basically identical. Smart cards with contacts follow ISO 7816. These MIFARE contactless cards are ISO 14443 Type A cards, and their protoco…

It would be more analogous to your wifi antennas looking like 6" cat 5 cables with an RJ-45 painted on the end :)

We’re almost there. Try zooming in to the first picture on this RJ45 connector:

https://www.truecable.com/products/cat6a-field-term-plug-shi...

At that price point, there should be a wifi module hidden in it somewhere :)

Re: The tiny chip that powers Montreal subway tickets

#417

Post by PaulRobinson »

scoot wrote: post #331
solarized wrote: post #324

To peoples asking: "Why not just QR codes?" Again it's all about latency. QR codes take longer when you tap them at the gate: opening the app, waiting for the scanner to adjust, connecting to inet. While NFC handle these tasks almost instantly. A big difference in super busy places where queues are a nightmare. Again, this problem wouldn't exist if we can optimize WFH methods. We don't need to solving "physical probl…

The UK rail network already supports QR codes, with the busiest station handling over 80M entries/exits per year. Meanwhile, the integrated subway/overground/bus network in London supports direct payment with NFC smartphones, without the need for an intermediate "smart" paper ticket; the infrastructure for vending those; or the (not insignificant) cost of producing the tickets. Not sure what Montreal was thinking!

Even better, London doesn’t need NFC smartphones: if you have a chip bank card with a chip for tap payments, just tap that. For those of us with smart watches, they do the metro fast pay thing as well, so I literally just tap my watch without having to press anything or get anything out of my pocket. If my watch battery is dead, I can just a bank card.

The only advantage to having Oyster is if you’re travelling enough to justify a monthly pass (daily and weekly caps are respected on bank card taps), or longer.

I travel a lot across North America and EMEA, always glad to get home and deal with London’s transport network: it’s the only one that is really designed around, built for and feels invested in the passenger experience.

Re: The tiny chip that powers Montreal subway tickets

#418

Post by woodruffw »

solarized wrote: post #324

To peoples asking: "Why not just QR codes?" Again it's all about latency. QR codes take longer when you tap them at the gate: opening the app, waiting for the scanner to adjust, connecting to inet. While NFC handle these tasks almost instantly. A big difference in super busy places where queues are a nightmare. Again, this problem wouldn't exist if we can optimize WFH methods. We don't need to solving "physical probl…

Why would a QR code require Internet, or an app? You could just print it on paper and track the corresponding balance on the server side. To my understanding this is what most transit networks do anyways, to prevent an enterprising user from modifying their balance on the card itself.

(The optical scanning argument makes sense, however.)

Re: The tiny chip that powers Montreal subway tickets

#419

Post by lxgr »

Reason077 wrote: post #261
lxgr wrote: post #225

Earlier quoted context omitted.

I think Oyster cards are still stored-value based, but I suspect that either the backend servers and connections are now fast enough to poll pending top-ups in real time, or they just fan out the pending top up dataset to all turnstiles. I remember using that feature in the SF bay area, and while it took a day for the top-up to actually propagate to all readers, it even worked on buses, so they must be uploading that…

The Oyster card balance is certainly maintained online in real-time (or near to real-time) since you can view it in the Oyster card app/website. But yes, for speed/redundancy they are still probably using the stored value balance too.

It's most likely near real time.

TfL likely need that mechanism primarily to synchronize the list of blocked open-loop bank cards with unpaid balances to all readers. Faster Oyster transaction list updates and any-station remote top-ups are probably just a side effect of that.

Clipper doesn't (yet) support open-loop bank cards yet, so for them, it's probably enough to update more remote readers every time the bus goes back to the depot, for example.

Re: The tiny chip that powers Montreal subway tickets

#420

Post by lxgr »

account42 wrote: post #375
lxgr wrote: post #191

Earlier quoted context omitted.

Both EMV and MIFARE (and similar solutions) indeed sit on top of ISO 14443-4 (or -3 for the older/lighter MIFARE versions), but they're conceptually very different: EMV is an account-based payments protocol, and the card only confirms its presence in a transaction; balances are managed on the backend. The reader does not authenticate itself to the card at all. MIFARE is a stored-value service and as such keeps track…

> MIFARE is a stored-value service and as such keeps track of the card's balance on-chip. This requires another smartcard on the reader side, holding the necessary keys for mutual authentication, but allows two-sided offline transactions, which is quite useful for transit applications (e.g. buses dropping out of network coverage, allowing higher volumes even during short server outages etc.) MIFARE cards are used in…

> a secure enclave for the keys doesn't even provide any additional security since they key is transmitted to the card anyway

I'd assume that the keys (more accurately passwords, since a key would never be transmitted to the card over an unencrypted interface) are diversified by card serial number though? In that case, it would still be useful to have an SAM to hold that diversification key. You could further store some MAC authentication tag on the password-protected tag that the SAM needs to see before revealing the password over the radio.

I'm not saying that this is how every transit system practically does use MIFARE Ultralight, but based on the design, it's definitely possible.

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