Secret Santa on Ethereum: how a ZK protocol stress-tests network privacy

The idea comes from an academic paper by Solidity engineer Artem Chistiakov and his co-authors and is now being refined in Ethereum research chats and community forums.

The protocol copies the mechanics of the classic Secret Santa game but moves it on-chain. Participants register their Ethereum addresses in a smart contract and confirm them with a digital signature to rule out multi-account setups and attempts to game the system. Then each person sends a random number through a special app without publicly revealing which address is behind that value.

Zero-knowledge proofs allow the contract to verify that everyone followed the rules without exposing the “address — random number” link. Next, the algorithm builds a permutation of “giver — receiver” pairs, making sure nobody is matched with themselves. The delivery details for the gift are encrypted based on the shared random numbers, so only the designated sender can decrypt them.

Even though it is wrapped in a festive theme, ZK Secret Santa is meant as a testing ground for more serious use cases: private airdrops, anonymous DAO voting, NFT raffles, and setups for whistleblowers who need to prove they belong to a group without revealing who they are.

At a broader level, the project fits into Ethereum’s current shift toward stronger privacy tools.

Vitalik Buterin regularly points out that without a privacy layer, the network risks turning into perfect infrastructure for total economic surveillance. The Ethereum Foundation has launched a Privacy Cluster, and projects like RAILGUN and Aztec Network are experimenting with “encrypted” balances and transactions on top of the base layer.

Right now, the team is preparing a reference implementation of the protocol in Solidity as open-source code. There is no firm date for a full launch yet, but developers are discussing rolling the system out to testnets by Christmas.

There are also challenges around gas costs and scalability. The proofs need to be light enough so that playing Secret Santa on Ethereum does not cost users as much as a complex DeFi transaction.

If the experiment works, ZK Secret Santa could become a basic template for a new wave of on-chain privacy protocols that try to combine blockchain transparency with a basic level of anonymity for people using Ethereum every day.