How are you guys? today I am going to talk deeper about the mobile security, I will take it from windows mobile side, because this what I have experience in, I am sure that there is similar in other mobile operating systems, first let us see this next picture,
This is image for smashed SIM card(I was done of it :D), here what is inside it, can u see the small chip, well it is real any SIM, has a very small processor with very small amount of memory, this cards called Smart cards, there is many many types of it, but let us get back to our point, SIM card is a type of smart cards that has processor and memory, for now it is OK, this thing has also something called Card OS, it is very small operating system, simply what it does is, it receive requests from the card reader, this card do the operation and reply back to the reader, the reader takes it and that's it, now what happens when Mobile starts up and try to have the signal from the mobile service provider, there is some kind authentication conversation must be done between the SIM and the Mobile network, what your device do is being a middle man, it takes result from SIM and give it to network, and take what network says and give it to Sim, that's cool for now.
The SIM card is divided into files, some files are protected and not readable by the reader, and some are password protected and some are open to be read with any kind of reader, I will try to add sample that explain all of that, here is some API's that may help any one to do SIM application related using windows mobile platform
To be continued
I hope that this post was informative and helpful.
Thanks for your time.