Privacy had a
blueprint in 2019.
What if a smart contract could verify a payment without publishing the balance? Zether explored that question on Ethereum. The name points back to that research.
This is an independent project. The original researchers and Anonymous Zether contributors are credited below; no affiliation or endorsement is claimed.
Encrypted balances.
Verifiable payments.
Benedikt Bünz, Shashank Agrawal, Mahdi Zamani and Dan Boneh introduced Zether: a confidential payment mechanism for smart contracts. Balances stay encrypted while cryptographic proofs let the contract check that a payment is valid.
The paper takes an account-based approach and introduces Σ-Bullets, combining Bulletproofs with Sigma protocols.
Read the 2019 Zether paperHide who pays whom.
Anonymous Zether implemented an anonymous extension of the original protocol. A transfer includes a public group of keys and encrypted balance adjustments, concealing the sender, recipient and amount within that group.
Its smart contract attaches to an existing ERC-20. Users deposit into Zether accounts, transfer privately and withdraw.
Explore Anonymous ZetherPrivacy inside
the token itself.
Our implementation puts the public ERC-20 balance and encrypted ledger in one token contract. There is no separate deposit contract. Public trading uses a Uniswap v4 pool against ETH on Robinhood Chain; private transfers use an eight-key ring.
We use ElGamal encryption on Baby Jubjub and Groth16 proofs. This differs from the original proof system. The live deployment is unaudited, and its proving key comes from a two-contributor setup plus a public beacon rather than a large public ceremony.
Inspect the mechanism and limitsSee the idea in action.
Create a key, buy or hide, and send inside a ring of eight.