AT88SC0404C-PI Atmel, AT88SC0404C-PI Datasheet - Page 38

• Manufacturer Part Number: AT88SC0404C-PI
• Manufacturer: Atmel

Specifications of AT88SC0404C-PI

• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Package Type: PDIP
• Mounting: Through Hole
• Pin Count: 8
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Not Compliant

5211C–SMIC–01/10
Atmel AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C
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
also decrements the 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
failure information of the authentication process and updates the attempts counter accordingly.
Key index:
Data :
Figure 21. Verify Crypto
Once the sequence has been carried out, the device requires the host to perform an ACK polling with either the Read
User Zone $B2 command or System Read $B6 command. To verify whether the authentication succeeded, the host
could either read the associated attempts counter to confirm the value is $FF, or read the post authentication
cryptogram from the device and compare with the cryptogram generated when the host computed the challenge bytes.
R
S
T
A
T
Command
b0000_00nn : Secret Seed G
b0001_00nn : Session Encryption Key S
Q : Host random number, 8 bytes
CH : Host challenge, 8 bytes
1011 1000
C
A
K
Key Index
000e 00nn
0
A
C
K
-G
3
Parameter 2
xxxx xxxx
0
-S
3
i
C
A
K
, and Secret Seed, G
0001 0000
N=16
A
C
K
Data x 16
d7--- ---d0
i
(or Session Encryption Key, S
i
and S
i
. The device utilizes the success or
A
C
K
S
O
P
T
i
). The device
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