Using Multiple Signature Blocks for Secure Boot and OTA Updates on ESP32-C3

[Muntazer]

Hello ESP Community,

I’m currently working on a project involving the ESP32-C3, and I’m exploring the implementation of secure boot and OTA updates using multiple signature blocks. I understand that the ESP32-C3 supports up to three signature blocks, and I’m curious about best practices and use cases for utilizing them effectively.

Here are my key questions:
Initial Firmware vs. OTA Updates: How can I best structure the first signature block for the initial firmware during manufacturing? Should this be signed with a common key, and how can I securely manage subsequent blocks for OTA updates?

Key Management: What are the recommended approaches for key rotation and management when using multiple signature blocks? Is it advisable to use different keys for each block?

Implementation Challenges: Are there common pitfalls or challenges that I should be aware of when implementing multiple signature blocks in a production environment?

Use Cases: Can anyone share specific use cases or scenarios where they found multiple signature blocks beneficial in their projects?

I appreciate any insights or experiences you can share. Thank you!