ATAES132-SH-EQ-T Atmel, ATAES132-SH-EQ-T Datasheet - Page 13

• 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

3.
3.1.
3.1.1.
3.1.2.
3.2.
3.2.1.
3.3.
Security Features
All ATAES132 security features are optional. Each feature is enabled or disabled by programming configuration bits in the
EEPROM configuration memory. Each user zone, key, and counter is separately and independently configured.
This section describes the ATAES132 security features and cryptographic capabilities. The functionality associated with each
portion of the memory is described in Section 2.
Architecture
The ATAES132 contains all circuitry for performing authentication, encryption and decryption using keys stored securely in the
internal EEPROM. Since the secrets are stored securely in the ATAES132, they do not have to be exchanged prior to
executing cryptographic operations.
The ATAES132 has fixed cryptographic functionality; it is not a microcontroller and cannot accept customer firmware. The
ATAES132 contains a hardware AES cryptographic engine and has a fixed command set. Although the functionality is fixed, it
is also flexible because each feature is enabled or disabled by the customer by programming registers in the EEPROM
configuration memory. After personalization is complete, fuses lock the configuration so that it cannot be changed.
AES
The ATAES132 cryptographic functions are implemented with a hardware cryptographic engine using AES in CCM mode with
a 128 bit key. AES-CCM mode provides both confidentiality and integrity checking with a single key. The integrity MAC
includes both the encrypted data and additional authenticate-only data bytes as described in each command definition. Each
MAC is unique due to inclusion of a nonce and an incrementing MacCount register in the MAC calculation.
See Appendix I for information about how the AES computations are performed. Hyperlinks to the AES standard are provided
in Appendix A.
Hardware Security Features
The ATAES132 chip contains physical security features to prevent an attacker from determining the internal secrets. The
ATAES132 includes tamper detectors for voltage, temperature, frequency, and light as well as an active metal shield over the
circuitry, internal memory encryption, and other various features. The ATAES132 physical design and cryptographic protocol
are designed to prevent or significantly complicate most algorithmic, timing, and side channel attacks.
Authentication
The authentication commands utilize AES-CCM to generate or validate a MAC value computed using an internally stored key.
The command set supports both one way and mutual authentication. One ATAES132 device can generate packets for
authentication of a second ATAES132 device containing the same key. The internal authentication status register remembers
only the most recent authentication attempt. A user zone can be configured to require prior authentication of a designated key
before access to the user zone is permitted.
Key Authentication
Individual keys can be configured to require a successful authentication prior to use. This requirement can be used to prevent
some kinds of exhaustive attacks on the keys. The authentication requirement can be chained to require authentication of
several keys prior to allowing a particular operation. The internal authentication status registers remember only the most
recent authentication attempt.
Encrypted Memory Read/Write
A user zone can be configured to require an AES-CCM encryption for the EEPROM read or write operations. If encryption is
required for write access, then the MAC is validated before the received (encrypted) data is written to the EEPROM. If
encryption is required for read access, then the ATAES132 encrypts data when it is read from the internal EEPROM and
generates an associated integrity MAC.
Atmel ATAES132 Preliminary Datasheet
8760A−CRYPTO−5/11
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