Using Opaque
Send privately
How a private transfer works, and what is still missing.
Soon
Private sending in the app.
What a private transfer is
One transaction spends up to two notes of one asset and creates two new notes. If the exit amount is zero, nothing leaves the pool: the value just moves from your notes to new notes, one of which can belong to someone else.
The chain sees two nullifiers (the spent notes, unlinkable to their commitments), two new commitments, and two encrypted blobs. It does not see the sender, the recipient or the amount.
How the recipient finds the note
The new note comes with an encrypted copy addressed to the recipient's key. Their wallet scans the encrypted copies and decrypts the ones meant for it. To send to someone, you need their receiving key.
Proof of payment
A private send can come with a proof of payment: a link that shows a recipient was paid an amount, and nothing about the sender. Soon. See Keys.