What a one-time secret is
A one-time secret is a piece of text, usually a password, a key or a short note, that can be read exactly once. It is delivered through a link. The first reveal shows the text and destroys the stored copy in the same operation, so the link cannot be opened a second time, by the recipient or by anyone who finds it later.
LinkPilot's version encrypts the text in your browser with AES-GCM-256 before it is sent. The key is placed after the # in the link, which browsers never transmit, so the server holds ciphertext and no key. That means we cannot read the secret, and neither can anyone who gets into our database.