A private zero-knowledge protocol named ZK Secret Santa has been introduced for Ethereum, enabling anonymous, trustless execution of a gift exchange.

The system was developed by Artem Chistyakov, head of Solidity at Distributed Lab and author of the Circom Witchcraft project.

Protocol details

ZK Secret Santa leverages zero-knowledge proofs to conceal participant addresses while preserving verifiability of the pairing process by a smart contract.

The protocol enforces a rule preventing any participant from being matched with themselves, with the distribution outcome provably correct on-chain.

Implementation and use cases

Deployment targets the Ethereum network and relies on smart contracts to remove any need for a trusted administrator during the exchange.

According to the project's description, this approach can be adapted for other simple on-chain games and user-focused privacy scenarios.

Properties

• Anonymity: participant addresses remain hidden from observers and other players, ensuring identity linkage cannot be recovered from on-chain transaction data.
• No self-selection: the protocol incorporates checks that mathematically prevent participants from being assigned to themselves during the matching process on-chain.
• On-chain verification: smart contracts validate the distribution results and verify zero-knowledge proofs without disclosing private information to any external observer.

Publication

The work is documented in a scientific paper posted on arXiv, which details protocol design, cryptographic assumptions and verification procedures.

The release illustrates practical privacy layers for simple Ethereum applications and underscores the expanding toolkit of zero-knowledge technologies for decentralized systems.