AT88SC0404CRF-WA1 ATMEL [ATMEL Corporation], AT88SC0404CRF-WA1 Datasheet - Page 5

• Manufacturer Part Number: AT88SC0404CRF-WA1
• Description: 13.56 MHz CryptoRF EEPROM Memory 4 Kbits
• Manufacturer: ATMEL [ATMEL Corporation]

Communication
Security
Security Methodology
Memory Access
5023CS–CRRF–12/06
Communication between the PICC and reader operates in three basic modes. Standard
mode is the default mode for the device after power-up and anticollision. Authentication
mode is activated by a successful authentication sequence. Encryption mode is
activated by a successful encryption activation, following a successful authentication.
Table 2. Configuration Security Modes
Notes:
Figure 3. Security Methodology
Depending on the device configuration, the host will carry out the authentication protocol
and/or present different passwords for each operation: read or write. To insure security
between the different user zones (multiapplication card), each zone can use a different
set of passwords. A specific attempts counter for each password and for the
authentication provides protection against systematic attacks.
Authentication
Encryption
Standard
Mode
Check Password (WPW)
Check Password (RPW)
1. Modification Detection Code
2. Message Authentication Code
Device (card)
Compute Challenge B
Checksum (CS)
Card Number
Challenge B
VERIFY CS
Write DATA
VERIFY A
User Data
encrypted
DATA
clear
clear
Passwords
encrypted
encrypted
clear
Data Integrity
MDC
MAC
MAC
Check
COMPUTE Challenge A
Challenge A
VERIFY B
Read Password (RPW)
VERIFY CS (optional)
Write Password (WPW)
DATA
CS
(2)
(2)
(1)
Host (reader)
5