Arm Limited Vigil Security, LLC Arm Limited This document specifies a firmware update mechanism where the firmware image is encrypted. Firmware encryption uses the IETF SUIT manifest with key establishment provided by the hybrid public-key encryption (HPKE) scheme and the AES Key Wrap (AES-KW) with a pre- shared key-encryption key. Encryption of the firmware image is encrypted using AES-GCM or AES-CCM.