hkdf-tree is at 0.1.0: the derivation is specified and covered by the RFC 5869 test vectors, and the determinism contract in docs/architecture.md is what future versions are held to. Treat it as young software nonetheless — review it before you put a master seed into it, and keep an independent recovery path until you have run a full restore drill (see docs/cookbook.md).

For security-relevant issues do not open a public GitHub issue.

Please contact the maintainer privately: dr.johannes.bruegmann@gmail.com, or via the GitHub profile of enk-ode.

In scope:

• Cryptographic correctness of the HKDF derivation.
• Handling of the master seed in memory (leaks via panics, error messages, swap, core dumps).
• Correctness of encoding functions (Diceware wordlist mapping, alphanumeric, numeric, base64).
• YAML parsing safety (untrusted inventory files).
• Report generation (QR code content leakage, PDF metadata leakage).

Out of scope:

• Weaknesses in the master seed itself (generation, backup, physical storage).
• Weaknesses in downstream services that consume the derived passphrases.
• Denial of service on the local machine running the tool.