zkBounce turns a message into a small, refundable promise. Here is the full lifecycle in plain language.
The lifecycle
- Post the bond. The sender posts a refundable USDC bond on Base. Payment happens before the message is sent over normal email.
- Deliver. The message is delivered. zkBounce does not read or store the message.
- Engage or ignore. The recipient replies, or does nothing. In both cases the sender is not penalised.
- Refund. The sender gets the full bond back.
- Spam settlement. If the recipient flags it as spam or abuse, the bond pays the recipient and the protocol.
A bond is not a fee. If you send mail people want, you pay nothing except the time your bond is locked.
Privacy, in plain words
Zero-knowledge proofs let someone prove a fact without showing the data behind it. zkBounce uses them so the outcome of a bond can be settled without revealing who sent what to whom. There is no server-side matching of senders and recipients, and email addresses are never committed on-chain.
Technical deep-dive (planned design)
Settlement is planned to use x402 v2 with USDC on Base.
The approach under evaluation reuses ZK Email-style proofs of DKIM signatures, and uses Noir with the Barretenberg proving backend. These choices are not final.
The smart contracts are unaudited and are in Phase 0 feasibility work. Nothing here is live.