Rob,

First, I appreciate your comments and I think they are perfectly valid for the "standard way of things".

However, I always like to have alternatives.

So depending on how far Mahmood (or his client) wants to go, he can or may not adhere to standards. Although usually taken for granted, for a really basic system the "filesystem" described in ISO 7816, part 4 is not needed at all. So all you need for what you call "framework" is implementation of ISO7816, 3 (strictly speaking) which is barely more than simple UART communication, and a sort of a cipher (try e.g. googling for "skipjack tea avr" :-) ); plus some basic insight and basic AVR (or PIC or whatever) programming skills.

Of course, there is more in the javacard, however, Mahmood may and may not find it useful. The cost paid in javacard is to be considered against the cost of developing his own "framework" plus the potential risk from being nonconformant.

Jan Waclawek