What did COTI achieve on Ethereum’s Sepolia testnet?

COTI demonstrated a solution to Yao’s “Millionaires’ Problem” using Garbled Circuits on Ethereum’s Sepolia testnet. The system allowed encrypted comparisons between users without revealing private data on-chain.

What is the “Millionaires’ Problem” in cryptography?

The Millionaires’ Problem is a famous cryptography challenge created by Andrew Yao in 1982. It asks how two people can determine who is wealthier without revealing their actual financial values.

Why is solving the Millionaires’ Problem important for blockchain?

The challenge represents a core benchmark for secure multiparty computation (MPC) systems. Solving it on blockchain infrastructure could enable privacy-preserving financial applications without exposing sensitive user data.

What are Garbled Circuits?

Garbled Circuits are a cryptographic technique allowing computations to occur on encrypted data without revealing the underlying information. The method is considered one of the most promising approaches for private blockchain computation.

How does COTI’s system protect privacy?

The implementation allows users to submit encrypted inputs while the computation occurs privately. Only the final result becomes visible, while the underlying values remain hidden from counterparties and the blockchain itself.

Why does this matter for Ethereum?

Ethereum has historically struggled to balance transparency with privacy. COTI’s deployment suggests encrypted computation may become possible within Ethereum-compatible environments without sacrificing decentralisation.

What practical use cases could this technology support?

Potential applications include private DeFi transactions, confidential institutional finance, secure voting systems and privacy-preserving smart contracts. The technology could help institutions use blockchain infrastructure without exposing sensitive data publicly.

What role did Soda Labs play in the project?

COTI said the infrastructure was developed in collaboration with Soda Labs. The system is already operational on COTI’s mainnet and compatible with Ethereum Virtual Machine development tools.

COTI brings private computation to Ethereum testnet

Written by Isaac FrancisPublished May. 8 2026Last Updated May. 8 2026

COTI demonstrated a solution to Yao’s “Millionaires’ Problem” on Ethereum’s Sepolia testnet using Garbled Circuits technology, marking a milestone for private computation on public blockchain infrastructure.

The demonstration allowed two parties to compare private financial values without revealing their underlying data to one another or exposing plaintext information on-chain.

Originally proposed by computer scientist Andrew Yao in 1982, the Millionaires’ Problem has long been viewed as a benchmark challenge for secure multiparty computation systems.

COTI said the implementation operates entirely through encrypted computation without requiring trusted intermediaries or centralised actors to verify the outcome.

The infrastructure was developed alongside Soda Labs and is already live on COTI’s mainnet, while remaining compatible with Ethereum Virtual Machine environments and Solidity smart contract development tools.

The company said the system could support future applications involving private decentralised finance transactions, confidential institutional data processing and privacy-preserving governance systems.

Ethereum co-founder Vitalik Buterin has previously highlighted Garbled Circuits as a promising approach for achieving cryptographic guarantees in secure multiparty computation while maintaining relatively high processing speeds.

The Sepolia deployment forms part of COTI’s broader “Privacy-on-Demand” initiative aimed at extending encrypted computation services across Ethereum and other blockchain ecosystems.

At the time of reporting, Ethereum price was $2,279.64.