End-to-end encrypted in your browser. Only the link holder can read it. We never see the plaintext.
Helps the recipient recognise what this is about. Do not put secret information into the label.
Optional second protection if you share the link over an unsafe channel. The link already contains the decryption key - this password is an extra layer, not a requirement for security.
Share this link with the recipient. It works exactly once; after that, the secret is destroyed.
Need the other direction? Ask someone for a secret via the request flow. Request a secret How does this work?