How lastpub works

You write a message and name its recipient before lastpub asks for your Nostr key. Your signer seals the message locally; the plaintext never leaves your browser.

1. Seal it. The encrypted message is time-locked and deposited with one tower.
2. Keep your pulse. Before release, the tower actively asks you for a signed proof of life.
3. Renew it. Your response moves the deadline and replaces the small time-lock capsule.
4. Or let it go. If the challenge and grace window expire, the tower publishes the last committed capsule.

Nostr carries the encrypted requests and responses. Drand supplies the independent release clock. The tower never receives the plaintext or your private key.