User's Manual

ACG HF Multi ISO RFID Reader V1.0
ACG Identification Technologies GmbH 122
13.3 What type of mifare
®
card should I use?
The mifare
®
standard is designed for multi-application environments. It contains 16
sectors each with 2 individual keys, access conditions, and 3 data or value blocks.
Some applications use the 1 Kbytes of the mifare
®
Standard Card Memory only as
storage area.
mifare
®
Ultralight has no crypto unit on chip. It only supports 16 blocks.
mifare
®
Standard 4k cards have the same features as mifare
®
Standard cards but
increased memory capacity.
13.4 How safe is mifare
®
Standard for cashless payment?
Security is always a feature of the overall system, not of the components. It requires
careful design.
A properly designed system will require ALL barriers to be hacked in order to be
broken.
For good design start identifying possible attacks and then create barriers to block
them.
mifare
®
was specifically designed for cashless payment applications. The mifare
®
concept provides the following security barriers:
• Anti-collision/-selection
• Atomic value transaction
• Ciphered communication
• Storage of values and data protected by mutual authentication
• Weak field keys that allow decrement only
• Stored keys in the reader that are not readable
• Keys in the card that are not readable
• A brute force attack based on trying many different keys is limited by the
transaction time (several ms) of the card and would last virtually forever.