AT88SC0104CA_11 ATMEL [ATMEL Corporation], AT88SC0104CA_11 Datasheet - Page 53

• Manufacturer Part Number: AT88SC0104CA_11
• Description: Atmel CryptoMemory Specification Datasheet
• Manufacturer: ATMEL [ATMEL Corporation]

10.9
10.9.1 Functional
Verify CRYPTO: $B8
Figure 10-6. Verify Crypto Command Functional Description
When the device receives the verify crypto command, it computes a challenge based on the received random number, Q, the
internally stored associated cryptogram, C
associated attempts counter. It then compares the computed challenge with the challenge sent by the host. If the challenges
match, the device computes and writes a new C
authentication process and updates the authentication attempts counter accordingly.
Key index:
Data :
8 random bytes
8 challenge bytes
b0000_00nn : Secret Seed G
b0001_00nn : Session Encryption Key S
Q : Host random number, 8 bytes
CH : Host challenge, 8 bytes
Host
Command
Key Index
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
CH1
CH2
CH3
CH4
CH5
CH6
CH7
CH8
0
-G
3
i,
and secret seed, G
0
-S
Device
i
3
and S
Atmel AT88SC0104CA/0204CA/0404CA/0808CA [Datasheet]
i
. The device utilizes the success or failure information of the
i
(or session encryption key, S
i
). The device also increments the
8664E−CRYPTO−12/11
53