Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [smart-card]

Smartcards go from memory-chips to ARM 32-bit architecture microprocessors on board. There used in a variety of industries from Telecoms(sim cards) to banking(EMV).

Smartcards refer to cards that have a chip inside, RFID(NFC) cards can also fall in to this definition.

The widest uses of smart cards are SIM cards used with GSM Networks and Credit/Debit cards.

Most smartcards have an OS with a file system on them with applets which are selected with various terminals.

Smart cards are communicated with using Application Protocol Data Unit(APDUs) which encapsulate the data in to a standardised method for transport.

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What's the need for conductive bridges between the regions of a smart card contact pad?

Here's a scan of a "chip-and-pin" Visa Electron contact pad It looks like a metal plate divided into regions by narrow cuts. Look for example at regions marked A and B - there's a cut between them but it only separates them partially and there's a…
sharptooth
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What is this weird EMV pin on my credit card?

I recently got a Venmo card, which is my first card with contactless support. I was looking at the EMV pins and noticed a very weird design. In the middle of the ground pin, there is this long, thin pin extending into it that I've never seen…
Ian Carroll
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What's the purpose of such weird wiring inside this smart card?

Here's a scan of a stripped MIFARE Ultralight smart card That's some plastic film with (I assume aluminum) foil wiring acting as the antenna for both powering the chip and providing radio communications. Two things look suspicious. First, there's a…
sharptooth
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Why are chips used in electronic identity cards?

Why did Germany choose NXP's SmartMX chip in the new Electronic ID Card (see here) instead of having a more conventional solution, like an old credit-card-like approach? In fact, the question is more general: Why is the chip solution considered the…
John Thomas
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Why is processing power and memory in smartcards so limited?

Why is it that common smartcards like the SLE5528 are almost always limited to <16K of available memory, and a very slow 8 bit processor? What is the limiting factor that makes it technologically/economically infeasible to raise these limits? EDIT:…
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Is there an electrical design reason for phone SIM cards being inaccessible until a battery is detached?

So far I haven't seen a cell phone that allows to detach the SIM card without first detaching the battery - the SIM card is placed behind the battery and inaccessible unless the battery is detached. I assume there's some electrical engineering…
sharptooth
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Why is outer turn of this smart card antenna wider than the other turns?

Here's a scan of a stripped MIFARE Ultralight smart card. Most of the wiring is the antenna which effectively consists of a single spiral track. The outer spiral turn clearly is a bit wider than the other turns while all the other turns have equal…
sharptooth
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How does rewinding a smart card antenna into a smaller coil leave it operational?

Here is a description of how one guy extracted the electronics from a smart card and then embedded it into a ring wearable on a finger. The card in question is more or less similar to the card in another question, the minor difference is that the…
sharptooth
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Design of an electronic device to disable remote access ability of contactless payment cards without visible alterations and damage to the card

Question: How could I build an electronic device which disabled the remote interaction functionality of contactless payment cards while not affecting the functions which are accessed via the on-card contacts or magnetic stripe (where equipped)? I am…
sharptooth
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Why would a wireless smart card antenna have one larger loop and three smaller loops instead of four similar size loops?

This image is originally from here. I added some annotations. The picture shows an x-ray shot of a smart card with wireless capability (and also a contact pad for direct connection to a terminal). The antenna is made of four loops of wire laid out…
sharptooth
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What is the difference between ISO/IEC 14443 and ISO 7816 smart cards

I am trying to build my own smart card decoder and I found that the smart card with the most popularity in terms of security and utility is the Mifare Desfire EV1 which is pretty much industrial grade. The second card I found was the Parallax…
Arnaud Dorval
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How do I shield a card like Visa payWave and MasterCard PayPass to block its communication?

This is basically a replication of this question on Personal Finance SE. Suppose there's a wireless smart card like Visa payWave or MasterCard PayPass or MIFARE Ultralight. The owner wants to temporarily shield it so that it's totally impossible for…
sharptooth
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Why does smart card antenna follow a "snake" pattern when approaching the chip?

This image is from this post which shows MasterCard plastic card being dissolved in acetone to have the circuitry extracted for further analysis (TL;DR further analysis failed because of chip protective features). Wires are a bit off because acetone…
sharptooth
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Serial Smart Card Readers

I have a smart card that is used with a Respironics CPAP machine. I need to read the data off of the card. I have the Windows software for the card but I don't have a card reader just yet. Many people say you need a specific MAKO DT3500 card…
Russ
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I need a chip identified: TI 36A2DKK

I got a Smart Card reader out of a laptop. There's not much going on on the board, just the card receptacle on one side, with the contact springs, and two ICs on the back side: A Cypress CY7C63001 A-SC USB micro controller, which is the bigger of…
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