Bitstream Authentication Using External Memory - 2023.2 English

Vitis Unified Software Platform Documentation: Embedded Software Development (UG1400)

Document ID
UG1400
Release Date
2023-12-13
Version
2023.2 English

The authentication of a bitstream is different from other partitions. The FSBL can be wholly contained within the OCM, and therefore authenticated and decrypted inside of the device. For the bitstream, the size of the file is so large that it cannot be wholly contained inside the device and external memory must be used. The use of external memory creates a challenge to maintain security because an adversary might have access to this external memory. When bitstream is requested for authentication, Bootgen divides the whole bitstream into 8 MB blocks and has an authentication certificate for each block. If a bitstream is not in multiples of 8 MB, the last block contains the remaining bitstream data. When authentication and encryption are both enabled, encryption is first done on the bitstream, then Bootgen divides the encrypted data into blocks and places an authentication certificate for each block.

Figure 1. Bitstream Authentication Using External Memory