Urgent!!!!!!!!!!! SAM Card

Question

Dear all,
I need to know whats the difference between the SAM card and a normal Java Card, I know that a SAM card is in SIM size and is used to be placed in POS terminals and does some cryptography works for POS terminal's program. I am asked to develop for a SAM card, but I don't know how to work with them, can I write a normal Java card applet and load it on them?
Would you please help me? This is an urgent issue! :-s
Any help would be appreciated!

Answer 1

1. The size has absolutely nothing to do with the actual use of the chip. It is just a form factor. Since SAMs typically reside in a terminal they need to be small, hence have a SIM format. Then I know of SAMs having the format of a bank card (e.g. in TV set-up boxes).
The physical characteristics are not that important. What matters are the signals as defined in ISO7816-3 (for contact cards that is).
2. The life of a card is usually limited by the number of read/write cycles of its memory (Flash or EEPROM). Modern cards have read-write cycles of at least 100.000.
So if the SAM only does computation and only uses RAM, the card can go on forever.
If you use a Java card to develop, make sure that you do not update memory - unless of course you must keep track of what happened in a log file.
3. There is absolutely no reason why SAM cards should be more expensive apart from the fact that there fewer and price usually depends on volume. Also the handling may be more complex (security !!). Apart from that they like any other card - they use the same basic hardware.
4. That is a matter of policy. For SAM using Java technology it is important that the logic cannot be modified after having loaded all applets. Hence one often removes or blocks the Global Platform load 'applet'.
For native cards this is easier since there is no way to load logic.
But again, this is purely a functional requirement - there is no compulsion to do so.
A SAM is just a normal card with different functionality built in. Think of a card as a small PC accepting APDU commands and giving responses in a format defined by ISO7816-4. A SAM is just the same - it follows the same standard (ISO7816).
Still, I'm surprised that you must develop a SAM, which from a security and performance point of view can be rather complex and yet you seem to have little experience with smartcards.
I suggest you start by writing down the functional specifications of your SAM independent of the technology. Then select a platform.
Developing a SAM using native code is quite complex and needs detailed knowledge of the hardware (which chip makers will not give to you), so I suggest you use a Java card instead.