Crazy idea: would it be possible to encrypt notes (from the browser) and upload it to your server?

If so, I can think of cool things to do:

• You can give each user a unique ID
• Each user can choose their own password
• ID and password is enough to restore all Notes, also on multiple devices
• Users could optionally tick a Note as "public" (those won't be encrypted)
• Users can ignore other IDs if the ID sends spam