The tiny chip that powers Montreal subway tickets • Hacker News Board

Re: The tiny chip that powers Montreal subway tickets

#321

Post by contingencies » Mon, Jun 24, 2024, 8:53 AM UTC

hnick wrote: post #276

grishka wrote: post #230

Earlier quoted context omitted.

The problem with QR codes is that they are read-only. I don't know about Montreal, but Moscow public transport uses similar paper tickets, also Mifare Ultralight, except you can get them for different number of trips. When you use your ticket, the turnstile or validator would increment those one-way counters so that the next one would know how many trips you have left. You can't do that with a QR code without either…

I think semi-persistent internet is not such a big deal for a lot of providers. For Opal here in Sydney AU it uses a connection for some features. Cards can be anonymous or assigned to an account, the account shows all your trips online, so there's some required connectivity for that. The cards have a smart chip, but credit cards or phones can now also just be tapped directly, so it needs to match up when you tap off…

Fun tangent: I hit a bug in Opal recently with the stored value cards. I was able to obtain a balance that read out higher on the exit turnstile than on a top-up machine. I'm pretty sure this was related to a recharge that failed and then eventually succeeded. Multiple top-ups later and the difference seems to persist.

Re: The tiny chip that powers Montreal subway tickets

#322

Post by onion2k » Mon, Jun 24, 2024, 8:55 AM UTC

TowerTall wrote: post #285

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…

One of my claims to fame was being part of the team that built the first online banking site for a bank in my country around 1997. One of the things you could do was pay certain types of widely used paper invoices. When I was brought on, the UI for this was just a standard HTML table with labels and input boxes. I decided to build a prototype with a paper invoice image as the background and a textboxes places where t…

Around the same time (2001) I worked for a startup that was doing the same thing but with Flash instead of HTML. We were building European export forms. People really liked the UI side of it.

Re: The tiny chip that powers Montreal subway tickets

#323

Post by innocenat » Mon, Jun 24, 2024, 9:04 AM UTC

karunamurti wrote: post #272

grishka wrote: post #230

Earlier quoted context omitted.

The problem with QR codes is that they are read-only. I don't know about Montreal, but Moscow public transport uses similar paper tickets, also Mifare Ultralight, except you can get them for different number of trips. When you use your ticket, the turnstile or validator would increment those one-way counters so that the next one would know how many trips you have left. You can't do that with a QR code without either…

Once I searched how Japan do the synchronization of the data in the IC card because I can't imagine how they handle all of the traffic for millions of people especially in the rush hour. So the solution is the transportation card is writable, and each train station acts like a small data center. They sync the data periodically to the main data center. I think the syncing tech is getting better, Japan train companies…

Japan railway companies in Kanto region are moving to QR code for individual ticket in 2027.

The bulk of the ticket will still be the Felica card though, because as far as I know neither the QR code or EMV open-loop system can handle required throughput of 60 persons/minute/gate.

Re: The tiny chip that powers Montreal subway tickets

#324

Post by solarized » Mon, Jun 24, 2024, 9:05 AM UTC

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 problems" from start to finish. Making, distributing, and recycling all those ticket papers.

No matter how advanced your transportation tech is, moving people long distances is still really costly. Sorry to "steer" this conversation into WFH and WFO topics.

Re: The tiny chip that powers Montreal subway tickets

#325

Post by crote » Mon, Jun 24, 2024, 9:15 AM UTC

TowerTall wrote: post #285

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…

One of my claims to fame was being part of the team that built the first online banking site for a bank in my country around 1997. One of the things you could do was pay certain types of widely used paper invoices. When I was brought on, the UI for this was just a standard HTML table with labels and input boxes. I decided to build a prototype with a paper invoice image as the background and a textboxes places where t…

In my country we used to have a heavily standardized type of money transfer card. It'd be used both for regular wire transfers in a "fixed payer, flexible payee" form where you'd get a booklet of them to fill out later, and "flexible payer, fixed payee" form you'd get mailed to your house to pay your bills, only having to write your account number on them, sign it, and mail it to your bank.

They were designed to be machine-readable from the start for easy processing at the bank, and one of the ways they did this was by having all the fixed data encoded in a special font. When we started using smartphone banking apps, you'd just be able to scan a bill with your phone and it'd immediately read out all the data, fill in the missing stuff, and you'd only have to tap "confirm" to do the actual payment.

Re: The tiny chip that powers Montreal subway tickets

#326

Post by BOOSTERHIDROGEN » Mon, Jun 24, 2024, 9:16 AM UTC

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…

https://atadistance.net/2024/05/31/jr-east-and-tokyo-private...

Re: The tiny chip that powers Montreal subway tickets

#327

Post by asah » Mon, Jun 24, 2024, 9:24 AM UTC

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…

1000s of people leaving a stadium faces the same latency: not a WFH/WFO issue

Re: The tiny chip that powers Montreal subway tickets

#328

Post by voidUpdate » Mon, Jun 24, 2024, 9:27 AM UTC

windex wrote: post #296

TeMPOraL wrote: post #164

Earlier quoted context omitted.

> The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the instructions miss one step. Thing I figured out assembling IKEA stuff in the past few years: if it seems like they skipped a step, look carefully at the details in pictures. Perhaps use a magnifying glass. There's going to be only one way to get from step N to step N+1, and all the informa…

Ikea also doesn't use Philips screws. They have pozidriv screws and need pozidriv bits if you dont want to strip the screw heads. I learned the hard way.

I've never had an issue using my normal Phillips head screwdrivers with Ikea stuff

Re: The tiny chip that powers Montreal subway tickets

#329

Post by The_Colonel » Mon, Jun 24, 2024, 9:30 AM UTC

stavros wrote: post #314

The_Colonel wrote: post #305

Earlier quoted context omitted.

> Your ticketing system cannot assume tickets in any form cannot be replicated- they can be and if you introduce such a vulnerability in your system, you will lose revenue Yes, the question is not whether such system would be abused, but how much. But this is in the end what businesses care about. Will QR codes be abused more than NFC chips? Likely yes. Will it produce a larger financial loss than the cost of the NFC…

A centralized system is how tags work already, so you can't toss your ticket to your friend behind you and have them reuse it.

These NFC chips have counters to deactivate themselves after the allocated number of trips has been reached.

Re: The tiny chip that powers Montreal subway tickets

#330

Post by crote » Mon, Jun 24, 2024, 9:30 AM UTC

lukan wrote: post #166

markus_zhang wrote: post #98

Earlier quoted context omitted.

I have found the same thing with my wife. I'm a technical person, but I'm extremely bad with tools and such, including the ticket thing. If no one shows me how to use it I'll probably figure out a way to insert it somewhere. My wife won't have any problem with this and other small tools. The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the ins…

"I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the instructions miss one step" But why do people make incomplete manuals? If I have a step by step guidance and it doesn't work, because some steps were left out, than this is just a wrong manual! (I share your frustration)

Because most companies view the manual as an afterthought. You've already bought it. What are you going to do if the manual is bad, return it? And even then, you're returning it to a third-party store - the manufacturer isn't going to care care. You bought an ShelfExpress for 50% off at Furniture Mart, can you really expect them to care?

Ikea, on the other hand, prides itself on user experience. Everything is Ikea-branded, so any complaint will come back to Ikea because the buck stops there. Everything is sold internationally, and they don't want to translate it into a dozen languages, so they have to make clear assembly diagrams. Their entire brand is built around having great assembly instructions!