Advanced Topics
- HSM Mode and the CKBunker to permit automated signing and remote access.
- You can view and download the source code on Github.
- Long and detailed discussion of PIN codes and the security element that holds the real secrets.
- Details of our encrypted backup files.
- Documented limitations, policy choices, and TODO items.
- Importing seed words into Electrum for funds recovery and other tips.
- How to use with Bitcoin Core.
- How developers can modify Coldcard to extend it.
- Memory map highlights.
Security Design and Architecture#
- Mk4 Secure Elements
- Mk4 Security Model
- Coldcard NFC
- Coldcard PIN Design and Operation
- More Advance Documentation and Design Information
Last update:
August 31, 2026