StarkWare launched OffMarket, allowing Polymarket users to trade privately

According to The Block, Starknet developer StarkWare has officially opened its privacy trading service OffMarket to the public, allowing users to trade on Polymarket without publicly associating their positions with their accounts.

The service has been undergoing limited testing since August, operating based on Starknet's zero-knowledge technology and shared privacy pool. Currently, the USDC deposit limit for each account is set at $1,000, and StarkWare has stated that it will adjust this limit based on demand and usage. Orders are still executed on Polymarket, facing the same buyers and sellers and market prices.

OffMarket is completely non-custodial, with users' private keys stored in the browser, and funds held in Starknet's open-source privacy pool. Polymarket positions are held in contracts by wallets derived from user signatures. OpenZeppelin completed an audit of the privacy pool contract in June, finding no serious or high-risk issues, and StarkWare completed formal verification the following month. StarkWare co-founder and CEO Eli Ben-Sasson stated that the project stems from his long-term investment in the field of financial privacy and mentioned that OffMarket is bringing zero-knowledge technology to Polymarket.

A spokesperson for StarkWare stated that OffMarket still cannot prevent others from identifying traders through transaction size or timing, and the market, prices, and transactions themselves remain public. Transfers of USDC from the shared pool to new wallets can also be seen.