PRIMATEs is a family of lightweight permutation-based authenticated encryption schemes. Each member is designed with a different trade-off between security and efficiency.

Deciding which scheme to use reduces to two parameters: the security level and the mode of operation. There are two security levels:

  1. 120 bits, the default recommendation, and
  2. 80 bits, recommended for extremely lightweight applications.

Once the security level is chosen, a more fine-grained trade-off can be made by picking a mode of operation:

  1. APE uses full-round permutations and backwards decryption to add robustness against nonce reuse and  release of unverified plaintext
  2. HANUMAN uses full-round permutations and forward decryption
  3. GIBBON is a variant of HANUMAN with reduced-round permutations for speed-critical settings

Current specification: primatesv1.1