ZK Secret Santa on Ethereum Uses ZK Proofs for Privacy Layer
- ZK Secret Santa lets Ethereum run private gift pairings using zero-knowledge proofs.
- Relayers and cryptographic checks reduce address linking on Ethereum’s public ledger.
- The protocol targets Ethereum privacy gaps that expose users and businesses on-chain.
Distributed Lab researchers have published a protocol that shows how the Ethereum cloud can run a Secret Santa game with privacy. The system uses zero-knowledge proofs to create giver to receiver links without exposing identities. It is designed to keep the draw correct on a public blockchain while keeping participants confidential.
The protocol is called ZK Secret Santa, or ZKSS. Researchers present it as a model for private on-chain coordination. They argue it addresses a core limitation of Ethereum, where most transaction details remain publicly visible.
Ethereum Privacy Push Meets ZK Proofs and the ZKSS Design
The release comes as privacy has moved higher on Ethereum’s agenda. Co-founder Vitalik Buterin has warned that weak privacy could push Ethereum toward surveillance rather than freedom. Distributed Lab links its work to that concern, and frames ZKSS as a practical proof of what privacy tooling could enable.
ZKSS relies on zero-knowledge proofs, which could prove a statement is true without revealing the data behind it. In this case, the proof could show a valid Secret Santa assignment was produced.
According to the report, private activity on Ethereum faces three major obstacles. The first is address exposure, since interactions usually reveal the sender’s address or allow it to be linked. ZKSS combines proofs with transaction relayers, so actions could be submitted without directly tying each step to a participant address.
The second obstacle is randomness. Ethereum does not provide true randomness that is safe for sensitive selection, so the protocol avoids relying on a single on-chain random source. Instead, participants contribute randomness values, and the protocol uses proof checks to prevent participants from assigning gifts to themselves.
The third obstacle is repeat participation without detection, described in the paper as a “double voting” problem. The protocol uses nullifier-based checks to prove that each participant performed required actions only once.
Three Step ZKSS Workflow for Private Matching on Ethereum
Artem Chystiakov, Distributed Lab’s head of Solidity, describes a three-step process that requires input from all players. The flow is deliberately not peer-to-peer, according to the researchers. The stated goal is to keep execution verifiable while avoiding identity exposure during coordination.
In the setup phase, participants register addresses in a Sparse Merkle Tree. That allows membership proofs later without publishing a full list structure in a way that adds extra linkability. The protocol also uses committed signature hashes as part of the process described in the research.
In the next stage, participants submit randomness values anonymously. The paper describes these values as serving as RSA public keys. They are used to support encrypted transmission of delivery address details, so participants could share shipping information without revealing pairings.
Related: Ethereum’s Buterin Proposes Pluralistic IDs for Web3 Privacy
The protocol uses several cryptographic primitives to support correctness. The authors list hash functions, ECDSA signature recovery, and Merkle proofs among the building blocks. These parts are used to bind steps together and to let other participants verify that rules were followed.
The researchers compare the system to a physical Secret Santa draw. In the analogy, each participant puts a random note into a hat and then draws another note to get an assignment.
ZKSS is presented against a broader backdrop of Ethereum privacy efforts. The source text points to projects such as RAILGUN and Aztec Network, which focus on shielding balances and transaction details while settling on Ethereum.
The same source text also links privacy to enterprise risk. Public ledgers could expose financial activity, supply-chain transactions, and wallet holdings. Those disclosures could create competitive intelligence risks and could identify targets by showing large balances.
Regulators are moving in parallel, using different framing. The Financial Stability Board highlighted in October that secrecy or data privacy laws could hinder cross-border crypto oversight. It warned that confidentiality rules could limit data sharing across jurisdictions.
