Datasheet

Table Of Contents

42. AES – Advanced Encryption Standard

42.1 Overview

The Advanced Encryption Standard peripheral (AES) provides a means for symmetric-key encryption of

128-bit blocks, in compliance to NIST specifications.

A symmetric-key algorithm requires the same key for both encryption and decryption.

Different key sizes are supported. The key size determines the number of repetitions of transformation

rounds that convert the input (called the "plaintext") into the final output ("ciphertext"). The number of

rounds of repetition is as follows:

• 10 rounds of repetition for 128-bit keys

• 12 rounds of repetition for 192-bit keys

• 14 rounds of repetition for 256-bit keys

42.2 Features

• Compliant with FIPS Publication 197, Advanced Encryption Standard (AES)

• 128/192/256 bit cryptographic key supported

• Encryption time of 57/67/77 cycles with 128-bit/192-bit/256-bit cryptographic key

• Five confidentiality modes of operation as recommended in NIST Special Publication 800-38A

• Electronic Code Book (ECB)

• Cipher Block Chaining (CBC)

• Cipher Feedback (CFB)

• Output Feedback (OFB)

• Counter (CTR)

• Supports Counter with CBC-MAC (CCM/CCM*) mode for authenticated encryption

• 8, 16, 32, 64, 128-bit data sizes possible in CFB mode

• Optional (parameter) Galois Counter mode (GCM) encryption and authentication

SAM D5x/E5x Family Data Sheet

AES – Advanced Encryption Standard

Datasheet

DS60001507E-page 1412