RFID - Elektor

5
Introduction to
Cards and Tags
Renke Bienert
This chapter provides an overview of the typical characteristics of (contactless) smartcards
and describes the standard MIFARE contactless smartcards, which are used as
much as possible in the practical part of this book (Chapters 8, 9).
5.1 Overview
5.1.1 Memory Cards and Microcontroller Cards
The first chip cards were purely memory cards, which essentially just stored data. Today,
however, this description is very limiting, as ‘simple’ storage cards have different
formats as well as different storage capacities compared to our smartcards. We also
expect more functions from smartcards today, such as security functions, counter functions
and value calculations.
copyright Elektor
Still, the term ‘memory card’ is quite commonly used in the smartcard arena. This term
is generally used for smartcards that a system operator can purchase as a ‘finished’
card and use directly. These are typically inexpensive and are used in large quantities
in many applications.
Reading and writing are the main features of these cards, usually associated with prior
authentication and encrypted data transmission. These days, some of these ‘memory
cards’ are in fact microcontroller cards, so, even if the user sees only a simple read and
write interface externally, the smartcard is running software on a microcontroller.
For us, microcontroller cards come into play when an operating system and software is
required in order to make use of the card in an application. It could be that the card
contains a generic operating system and an application may be uploaded as software
(for example, a Java applet).
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