Sub Rosa – End-to-end encrypted secret sharing with client-side encryption

Summary: Sub Rosa is a zero-knowledge secret sharing tool that encrypts messages locally in the browser using the Web Crypto API. The encryption key is stored in the URL hash and never reaches the server, which only stores encrypted data that is deleted after reading.

What it does

It encrypts messages client-side and stores only encrypted blobs on the server, with keys embedded in the URL fragment. Messages self-destruct after being read.

Who it's for

Users who need secure, private secret sharing without server-side key exposure.

Why it matters

It prevents servers from accessing encryption keys or plaintext, enhancing message confidentiality.