The ATAES132 is a 32kb EEPROM that can be encrypted with AES using a 128-bit key using the Counter with CBC-MAC (CCM) mode. CCM provides an authenticated encryption mode. With an encrypted EEPROM, you can store small amounts of data-at-rest more securely. The ATAES132 also has the ability to encrypt and decrypt small packets of up to 32 bytes and return the result over the bus. The AES key remains in the device at all times.
At the time of writing this, there isn't a Linux driver for the ATAES132 device, but Atmel provides full documentation and an AVR-based library on their website at http://www.atmel.com/devices/ataes132.aspx.
