ATAES132-SH-EQ-T Atmel, ATAES132-SH-EQ-T Datasheet - Page 27

• Manufacturer Part Number: ATAES132-SH-EQ-T
• Description: EEPROM AES 32Kbit EE SPI
• Manufacturer: Atmel

Specifications of ATAES132-SH-EQ-T

• Rohs: yes
• Maximum Clock Frequency: 10 MHz
• Operating Supply Voltage: 6 V
• Maximum Operating Temperature: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8
• Interface Type: SPI
• Factory Pack Quantity: 4000

7.
7.1.
7.1.2.
7.1.3.
Command Definitions
The ATAES132 extended command definitions are described in this section. The commands are listed in alphabetical order
by command name. The standard Serial EEPROM read and write commands are in Section 5 which are not included in this
section. The cryptographic operations performed by the ATAES132 commands are described in Appendix I.
Auth Command
The Auth command performs a one-way or mutual authentication using AES-CCM. The Auth command options are shown in
Table 7-1. The nonce register value is used as the CCM nonce for all Auth command MAC calculations.
Table 7-17. Auth command options
If a MAC is required or will be generated by the Auth command, then a valid nonce is required. If the
KeyConfig[AKeyID].RandomNonce bit is 1b, then the nonce must be random.
The AuthCompute command can be used to generate the InMac required for inbound only authentication, or mutual
authentication (see Section 7.3). The AuthCheck command can be used to validate the OutMac (see Section 7.2).
In the I
specifications.
Authentication Status Register
The authentication status register contains the AKeyID, the AuthComplete status flag, and the usage bits. Prior to executing
the Auth command, the AuthComplete status flag is set to NoAuth. If the InMAC is successfully verified in the inbound only or
mutual authentication mode, then the AuthComplete status flag is set to YesAuth.
The ATAES132 authentication status register only stores the result of the most recent authentication attempt. If there is a
parsing or execution error then the prior authentication, status will be lost.
Authentication Usage
The usage field (Param2) controls which operations are permitted with a successful inbound only or mutual authentication (see
Table 7-2). If Param2 is 0x0000 the AuthComplete flag is set to NoAuth but the authentication outputs are generated. Param2
is ignored if the outbound only authentication is performed.
Mode bit 1
1b
1b
0b
0b
•
•
•
•
Mutual authentication
Outbound only authentication
Inbound only authentication
Authentication reset
The InMAC is verified, and upon success, an OutMAC is calculated and returned to the host. The AuthComplete
status flag is set to YesAuth if the InMAC is verified.
The OutMAC is calculated and output to the host. The AuthComplete status flag is set to NoAuth. The Outbound
only authentication is also known as challenge-response authentication.
The InMAC value is verified, and the success or failure is reported to the host. The AuthComplete status flag is set
to YesAuth if the InMAC is verified.
The AuthComplete status flag is set to NoAuth.
2
C interface mode, the Auth command can also used for Auth signaling. See Section J.5 for the Auth signaling
Mode bit 0
1b
0b
1b
0b
Description
Mutual authentication
Outbound only authentication
Inbound only authentication
Authentication reset
Atmel ATAES132 Preliminary Datasheet
InMAC
Required
Prohibited
Required
Prohibited
8760A−CRYPTO−5/11
OutMAC
Generated
Generated
No
No
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