The "Privacy Boost" logo of Toss, Optimism and Sunnyside Labs. [Provided by Toss]
The "Privacy Boost" logo of Toss, Optimism and Sunnyside Labs. [Provided by Toss]

Toss announced Wednesday that it has joined forces with global Layer 2 blockchain Optimism and privacy solution developer Sunnyside Labs to explore the feasibility of a won-backed stablecoin by validating digital financial infrastructure. The three companies signed an MOU and plan to conduct a proof-of-concept over the next three months.

The core focus of the PoC is to assess whether Optimism's key technology, the OP Stack, can be applied to blockchain-based digital financial infrastructure in South Korea. To determine whether the system meets the regulatory and security standards of mainstream finance, the companies will verify three criteria: whether financial institutions can directly control payment and settlement processes, whether know-your-customer and anti-money-laundering (KYC/AML) requirements can be technically implemented, and whether individual transaction data can be securely protected even on a public network.

Each company takes on a distinct role. Optimism, the Layer 2 blockchain, is responsible for the blockchain-based infrastructure. Layer 2 is a blockchain scaling technology that leverages Ethereum's security and settlement functions while enabling faster and cheaper transaction processing. L2 is a supplementary blockchain introduced to address the speed limitations and high transaction fees of existing blockchains such as Ethereum. More than 30 chains operated by major global exchanges and companies — including Soneium, World Chain, Unichain, OKX's X Layer and Kraken's Ink — currently run on the OP Stack.

Sunnyside Labs, the official core developer for Optimism, handles the privacy technology. Blockchain networks have traditionally been ill-suited for financial services because all transaction records and balances are publicly visible. Sunnyside Labs' "Privacy Boost" solution addresses this by concealing sensitive information from outside parties while still allowing financial institutions to access the transaction records they need. This enables customer data protection on a par with traditional finance even on a public network, making it possible to process large-scale transactions reliably and accommodate many customers at the same time.

Through the partnership, Toss aims to design dedicated infrastructure optimized for monetary transactions and services on top of Ethereum-level trust and security, and to connect it freely with other chains. The company plans to gradually expand its experiment of integrating blockchain infrastructure with its roughly 30 million subscribers and more than 500,000 online and offline payment touchpoints.

Kyle Jenkin, chief business officer of Optimism, said South Korea is one of the most sophisticated financial ecosystems in Asia, and that Toss, which has led the digital transformation of Korean finance, has already internalized compliance and security infrastructure on par with mainstream financial institutions. "We will demonstrate the performance and privacy standards of the OP Stack to meet Toss's sophisticated technical requirements, and we are excited to be working with the most trusted partner in the market," he said.

Kim Gyu-ha, chief business officer of Toss, said strict regulatory compliance and robust privacy protection are essential for Web3 technology to be successfully integrated into mainstream finance. "We will use the proven OP Stack to verify the feasibility of building a highly reliable, compliance-based digital financial infrastructure optimized for the Korean market," he said.


won@heraldcorp.com