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> 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 techn

by amluto 2y ago

> 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 protocol follows ISO 7816-4. This shouldn’t be terribly surprising — the entire ecosystem built for smart cards with contacts wants to support contactless cards with minimal changes, and this includes the host software, the readers, and the logic in the cards. There are even plenty of devices where the same device supports contact and contactless uses — plenty of credit cards, bank cards, and FIDO devices are like this. This is analogous to WiFi and wired Ethernet. They’re have very different physical layers, but they are logically compatible, and the same software supports both.

lxgr 2y ago
Only ISO 14443-4 uses the same protocol as ISO 7816 (another way of saying this is that ISO 14443-4 represents the higher layers of ISO 7816 over a different physical interface), though. MIFARE Ultralight does not actually implement 14443-4/7816/"smartcard"-style APDUs; it's significantly simpler, since the ICs are much less powerful. To make things more confusing, some MIFARE ICs really do implement ISO 14443-4 (e.g. their fixed-function MIFARE DESfire cards, and their programmable smartcard ICs like SmartMX), but not all of them.
m463 2y ago
It would be more analogous to your wifi antennas looking like 6" cat 5 cables with an RJ-45 painted on the end :)
- schmidtleonard 2y ago
  ...and now I want one.
- amluto 2y ago
  We’re almost there. Try zooming in to the first picture on this RJ45 connector: https://www.truecable.com/products/cat6a-field-term-plug-shielded https://www.truecable.com/products/cat6a-field-term-plug-shi... At that price point, there should be a wifi module hidden in it somewhere :)
  - xnzakg 2y ago
    Two things spring to mind: a whole computer inside an SFP module[1] and the O.MG cable[2] [1]: https://blog.benjojo.co.uk/post/smart-sfp-linux-inside https://blog.benjojo.co.uk/post/smart-sfp-linux-inside [2]: https://shop.hak5.org/products/omg-cable https://shop.hak5.org/products/omg-cable
TowerTall 2y ago
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 the numbers appearred on the paper invoice. When people paid the invoice, they would have the paper version they had received by postal mail next to them. Now, their mission was to enter the numbers so they would end up with a visual one-to-one copy of the paper invoice on the computer screen. It made it easy for everyone to figure out which numbers to enter. People embraced this immediately, and all forms were changed to follow this principle. All banks implemented it in their banking apps and still use it today.
- onion2k 2y ago
  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.
- crote 2y ago
  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.
deleted 2y ago
[deleted]

by amluto 2y ago

lxgr 2y ago

Only ISO 14443-4 uses the same protocol as ISO 7816 (another way of saying this is that ISO 14443-4 represents the higher layers of ISO 7816 over a different physical interface), though. MIFARE Ultralight does not actually implement 14443-4/7816/"smartcard"-style APDUs; it's significantly simpler, since the ICs are much less powerful. To make things more confusing, some MIFARE ICs really do implement ISO 14443-4 (e.g. their fixed-function MIFARE DESfire cards, and their programmable smartcard ICs like SmartMX), but not all of them.

m463 2y ago

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

schmidtleonard 2y ago
...and now I want one.
amluto 2y ago
We’re almost there. Try zooming in to the first picture on this RJ45 connector: https://www.truecable.com/products/cat6a-field-term-plug-shielded https://www.truecable.com/products/cat6a-field-term-plug-shi... At that price point, there should be a wifi module hidden in it somewhere :)
- xnzakg 2y ago
  Two things spring to mind: a whole computer inside an SFP module[1] and the O.MG cable[2] [1]: https://blog.benjojo.co.uk/post/smart-sfp-linux-inside https://blog.benjojo.co.uk/post/smart-sfp-linux-inside [2]: https://shop.hak5.org/products/omg-cable https://shop.hak5.org/products/omg-cable

TowerTall 2y ago

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 the numbers appearred on the paper invoice. When people paid the invoice, they would have the paper version they had received by postal mail next to them. Now, their mission was to enter the numbers so they would end up with a visual one-to-one copy of the paper invoice on the computer screen. It made it easy for everyone to figure out which numbers to enter. People embraced this immediately, and all forms were changed to follow this principle. All banks implemented it in their banking apps and still use it today.

onion2k 2y ago
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.
crote 2y ago
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.

deleted 2y ago

[deleted]