Project TailNumber is a signing service; please treat it accordingly.
The implementation is maintained privately. Report suspected vulnerabilities privately to the maintainers — do not open a public issue. Include reproduction steps and impact; you will get an acknowledgement and a remediation timeline.
- Keys are generated inside a PKCS#11 token and are non-extractable — today a SoftHSM2 software-HSM (the validation stand-in the live demo runs on); production is a Thales TCT Luna T-Series (T3000) HSM (FIPS 140-2 L3) under M-of-N quorum, the same code path.
- Every operation is written to a hash-chained, tamper-evident audit log.
- Signatures are independently verifiable offline against the published root.
- Dev-mode is intentionally open; production uses reverse-proxy identity (mTLS / SSO / LDAP) plus dashboard Basic auth.