Privacy Boost Powers Toss and KOMSCO's Onchain Payment PoC

Toss, Korea's largest fintech, and the Korea Minting and Security Printing Corporation (KOMSCO) announced today that they have completed a proof of concept for an onchain payment infrastructure. The PoC ran the full lifecycle of Korea's local currency vouchers onchain, from top-up to merchant payment to settlement.

Privacy Boost was the privacy infrastructure inside that flow. Here is what was tested, why privacy was a hard requirement rather than a nice-to-have, and what it signals for regulated finance onchain.

What Toss and KOMSCO built

The two organizations set up a test environment for local currency vouchers. On it, they ran a complete payment journey: topping up voucher tokens, paying with them, and settling onchain.

Unlike conventional card payments, where a merchant waits days to receive funds, settlement here happens at the moment of payment, and the merchant can move funds whenever they choose.

In the Toss and KOMSCO PoC, Privacy Boost was applied to the payment flow so that transaction information was never exposed in public. Voucher payments and merchant settlements executed onchain without broadcasting who paid whom and for how much. Toss and KOMSCO retained complete visibility over the system they operate.

This is the same model traditional finance has always run on. Your bank sees your transactions. The public does not. Privacy Boost brings that model to a public blockchain without giving up the settlement speed and cost advantages that made the chain worth using in the first place. The OP Stack served as the underlying blockchain infrastructure for this PoC, chosen for its proven robustness in production.

Why this matters beyond Korea

Most conversations with institutions about onchain adoption get stuck at the same place: the radical transparency of public blockchains. Everything is visible to everyone, which is disqualifying for anything involving customer data. The usual answer is a permissioned chain, which gives up most of what makes onchain worthwhile: shared liquidity, composability with existing applications, and neutral settlement that no single party controls.

The Toss and KOMSCO PoC shows another path working end to end: a permissionless blockchain, a compliant privacy layer, and a real public payment product running across all of it. As Toss put it in the announcement, public payment infrastructure is used daily, so stability and personal data protection have to be confirmed first. That is the premise Privacy Boost was designed around.

What comes next

This PoC is one of several engagements Privacy Boost is running with Toss across local currency and stablecoin payments. We will share more as those move forward.

If you are building payment, treasury, or settlement products for regulated institutions and the public ledger is what is holding you back, we would like to talk.