Safety numbers

A safety number is a short fingerprint so you can confirm you’re encrypting to the right colleague — similar in spirit to Signal-style verification. Encryption works without it; verification raises confidence you’re not sealing to the wrong key.

When to verify

• First time you message someone sensitive
• After a device change if your org’s practice requires it
• Anytime something feels off about a contact

How

1. Open the contact in mutande.
2. Compare the safety number (or scan QR on a device that supports it).
3. Mark verified once it matches out-of-band (call, in person, etc.).

Verification is a human trust step — mutande can’t replace a quick “does this match?” check with someone you already trust.

Next: encryption · what the hub sees.