Toss, one of South Korea's largest financial apps, has launched a pilot program to test blockchain technology that could eventually support a stablecoin pegged to the Korean won. The platform serves around 30 million users, allowing them to make payments, transfer money and access a wide range of financial services.
The company announced a three-month trial in partnership with Optimism and Sunnyside Labs. The project aims to determine whether a public blockchain can meet the performance, security and compliance standards required by financial institutions.
During the pilot, the partners will focus on three key areas. The first is payment settlement and whether financial institutions can directly manage the settlement process. The second involves compliance with Know Your Customer (KYC) and Anti-Money Laundering (AML) regulations. The third focuses on protecting sensitive transaction data while maintaining regulatory oversight.
Optimism will provide the blockchain infrastructure using its OP Stack technology, while Sunnyside Labs will deploy its Privacy Boost solution to safeguard confidential information. On most public blockchains, transaction details and wallet balances are visible to all network participants. Privacy Boost is designed to keep this information private while still allowing financial institutions to verify transactions and comply with regulatory requirements.
The companies will also evaluate whether the infrastructure can handle a high volume of transactions simultaneously, a critical requirement for supporting large-scale payment services.
Toss currently serves more than 500,000 online and offline merchants. If the pilot proves successful, the company plans to gradually expand the use of blockchain technology across its financial services.
According to a Toss representative, the project is intended to demonstrate whether it is possible to build infrastructure that combines Ethereum's security with a system specifically designed for financial services based on the Korean won. Another important objective is ensuring interoperability with other blockchain networks.
The trial is built on OP Stack, Optimism's modular Layer 2 technology. The solution processes transactions off Ethereum's main network before publishing the final results on-chain. This approach reduces transaction costs while increasing processing speed. Through the pilot, Toss will assess whether such an infrastructure could serve as the foundation for a nationwide digital payments system.
The initiative highlights how blockchain technology is increasingly moving beyond cryptocurrency applications. More financial companies are exploring its potential as part of next-generation payment infrastructure. If projects like this prove successful, blockchain could become an integral part of everyday financial services—even if most users never notice it operating behind the scenes.
