South Korea’s leading financial super app Toss is taking another step toward blockchain-based payments by partnering with Optimism and Sunnyside Labs to test infrastructure for a South Korean won-linked stablecoin. The collaboration will explore whether public blockchain technology can meet the security, compliance, and performance standards required for large-scale financial services.
The three-month pilot reflects growing interest among financial institutions in using blockchain technology for regulated digital payments while maintaining user privacy and meeting strict compliance requirements.
Toss launches stablecoin infrastructure trial
According to a press release shared with crypto.news, Toss has signed a strategic agreement with Ethereum Layer-2 network Optimism and blockchain privacy developer Sunnyside Labs.
The partnership will run a three-month proof-of-concept (PoC) designed to evaluate whether blockchain infrastructure can support institutional-grade payment systems for a South Korean won-linked stablecoin.
Rather than launching a stablecoin immediately, the project focuses on testing the underlying technology needed to support secure, scalable, and compliant digital payments.
Three key areas will be evaluated
During the trial, the companies will assess whether blockchain technology can meet the operational standards expected by financial institutions.
The pilot will focus on three major areas:
- Payment and settlement infrastructure
- Compliance with Know Your Customer (KYC) and Anti-Money Laundering (AML) regulations
- Privacy protection for sensitive financial transactions
The goal is to determine whether public blockchain networks can provide both transparency and confidentiality while satisfying regulatory requirements.
Privacy remains a major focus
One of the biggest challenges for financial institutions using public blockchains is protecting confidential customer information.
Normally, blockchain transactions and wallet balances remain visible to network participants.
To address this issue, Sunnyside Labs will integrate its Privacy Boost technology into the project.
The solution is designed to keep sensitive payment data private while still allowing regulated institutions to verify transactions and comply with financial regulations.
According to the project partners, this approach aims to balance blockchain transparency with the privacy standards expected in traditional financial services.
Optimism’s OP Stack powers the infrastructure
The technical foundation of the pilot will be built on Optimism’s OP Stack, a modular Layer-2 blockchain framework designed to improve Ethereum’s scalability.
Instead of processing every transaction directly on Ethereum, Layer-2 networks execute transactions separately before settling them on Ethereum’s main blockchain.
This approach offers several advantages, including:
- Lower transaction costs
- Faster settlement speeds
- Higher transaction capacity
- Ethereum-level security
Toss will evaluate whether a dedicated blockchain built on OP Stack can better support Korean payment services than relying solely on shared public blockchain infrastructure.
Toss prepares for broader blockchain adoption
Toss currently serves approximately 30 million users and supports more than 500,000 online and offline merchants across South Korea.
The company said it plans to gradually expand blockchain experiments throughout its payment ecosystem if the pilot proves successful.
A Toss representative explained that the objective is to verify whether Ethereum’s security, combined with a dedicated blockchain optimized for local currency payments, can support future financial services while remaining interoperable with other blockchain networks.
Optimism continues expanding enterprise adoption
Optimism has become one of the most widely adopted Layer-2 ecosystems within Ethereum.
Its OP Stack technology already powers more than 30 blockchain networks, including projects developed by:
- Sony
- World Chain
- Uniswap
- OKX Layer
- Kraken
The platform also provides enterprise-focused blockchain deployments designed to meet regulatory and institutional security requirements.
Several regulated financial companies, including European fintech platform Bitpanda, have already adopted Optimism’s infrastructure.
Growing interest in blockchain-based payments
The Toss partnership reflects a broader trend of financial institutions exploring blockchain technology for real-world payment systems.
Rather than focusing solely on cryptocurrencies, many companies are now developing infrastructure capable of supporting regulated stablecoins tied to national currencies.
If successful, the project could demonstrate how public blockchain networks can support secure payment settlement while meeting compliance, privacy, and scalability requirements expected by regulators and financial institutions.
Final thoughts
Toss’s partnership with Optimism and Sunnyside Labs highlights South Korea’s growing interest in blockchain-powered financial infrastructure. By testing a won-linked stablecoin framework on Ethereum’s Layer-2 technology, the companies aim to determine whether blockchain can support institutional payment systems without compromising security, compliance, or user privacy.
While the initiative remains an early-stage technology trial, its outcome could influence how financial institutions approach stablecoin payments and blockchain adoption in the years ahead.
