Can you use a simcard to act as a micro or simple computer? - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: October 13, 2019, 04:33:17 am
content: I was reading about simcards and they seem like little computers that run at 30mhz. I would guess it doesn't have much memory but can you program them to do anything useful? Be cool if you could make use out of all your old sim cards, or have something that tiny yet durable and swappable do something useful. Obviously I/O is a problem off that few pins but maybe there is a way to connect the data out to something that would take serial to 8 pin or 16 pin bus?

author: ebclr
author_rank: Super Contributor
timestamp: October 13, 2019, 05:46:12 am
content: It's totally possible, not in all cards, but in many kinds of smart cardshttps://youtu.be/CwBAFwjyDDI

author: soldar
author_rank: Super Contributor
timestamp: October 13, 2019, 06:58:45 am
content: ASIM cardand aSmart Cardare different things.I believe the SIM is mostly just memory and has little or no processing power whereas a Smart card is ... smarter.

author: Berni
author_rank: Super Contributor
timestamp: October 13, 2019, 07:30:58 am
content: Quote from: soldar on October 13, 2019, 06:58:45 amSIM Cards do need computation. The cell network uses them as part of the encryption chain to keep other people from listening in on your calls trough RF or to impersonate you on the network and get to use your phone number.SIM cards are just application specific SmartCards. The main point of these things being that instead of being just memory they also have the capability to run encryption algorithms on the card itself. This lets them keep keys in a secret inaccessible area where it uses them upon getting a request to encrypt something. Because of this it is impossible to clone such a card as there is no conventional way of reading out the keys. The cards also provide additional security functionality such as a PIN code check. Phone SIM cards use this where when typing in the PIN code, the code it sent to the card and the card verifies if the code is correct. Upon receiving too many failed attempts the card locks itself down.And before you jump on it. Yes it is possible to extract the secret keys from a smartcard, but it usually involves decaping the silicon die and probing/fault injecting directly on its circutry. But its a process that is too difficult to be worth it on a SIM or Bank/Credit card, so you can effectively consider them impossible to clone. However they do happen to use SmartCards to generate decryption keys for satellite and digital cable TV, so people are hacking into those SmartCards because they can sell the cloned subscriber cards for a lot of profit. As a result these satelite TV smartcards are the most secure type of smartcards in the world, the ones used for banking are actually the least secure because there is little risk involved and banks have to issue a crap ton of them, so they use the cheapest kind.

author: tooki
author_rank: Super Contributor
timestamp: October 13, 2019, 01:35:42 pm
content: Quote from: soldar on October 13, 2019, 06:58:45 amAbsolutely wrong. The SIM card does things like encryption. And SIM cards aren’t even really dedicated SIM cards, insofar as the “SIM” is actually an application on the card!There’s a really interesting video about this on YouTube, from some hacker conference. I highly suggest watching it:https://youtu.be/31D94QOo2gY

author: Beamin
author_rank: Super Contributor
timestamp: October 14, 2019, 08:11:09 pm
content: Quote from: ebclr on October 13, 2019, 05:46:12 amWhat does ashok's induction coil LEDs have to do with anything? I'm guessing that's what it is in all 26 seconds of generic obnoxious techno music in that video. .