Definition of Key Purpose for Sony IMX623 and IMX728 Camera Drivers#

The camera device driver interprets the key purpose in camera configuration. NVIDIA DRIVE®OS provides default drivers for IMX728 and IMX623 camera drivers by default and defines following options for the keyPurpose configuration field:

  1. keyPurpose: “IMG_GMAC” - GMAC-AES-128 key is used for the GMAC verify operation on frame data.

  2. keyPurpose: “IMG_ECB” - ECB-AES key is used to decrypt an encrypted GMAC tag passed from a sensor with each image frame metadata.

  3. keyPurpose: “I2C_CMAC” - AES-CMAC-128 key that the camera driver uses to verify the integrity of all I2C transactions (read and write) with the camera.

For additional information about how these keys, refer to the specification for IMX623 or IMX728 sensors from Sony, the camera vendor.