ABSTRACT
The Smart Knowledge Provider and the CAD use a mutual active authentication protocol to identify each other. The card generates a random number and sends it to the CAD, which encrypt the number with a shared encryption key before returning it to the card. The card then compares the returned result with its own encryption. The pair may then perform the operation in reverse.
Once communication is established, each message between the pair is verified through a message authentication code. This is a number that is calculated based on the data itself, an encryption key, and a random number. If data has been altered (for any reason, including transmission errors) message must be retransmitted. Alternatively, if the chip has sufficient memory and processing power, the data can be verified through a digital signature.
The most common encryption methods are symmetric DES (Data Encryption Standard), 3DES (triple DES) and public key RSA (Rivest-Shamir-Adleman's algorithm), allowing up 56, 168, and 1024 bit long keys, respectively.

TABLE OF CONTENT
TITLE PAGE                                   
CERTIFICATION                               
APPROVAL                               
DEDICATION                                   
ACKNOWLEDGEMENT                       
ABSTRACT                                   
TABLE OF CONTENT