Toss has completed a blockchain-based public payment infrastructure proof of concept (PoC) with the Korea Minting and Security Printing Corporation. The project tested a structure that links an existing public payment system with blockchain and handles everything from payment to merchant settlement to prepare for the possible use of digital currency in real-world payments and settlements.

Viva Republica, which operates Toss, said on Sept. 18 it had completed the PoC with the Korea Minting and Security Printing Corporation for a blockchain-based public payment infrastructure.

The verification was a follow-up to a strategic memorandum of understanding signed by the two organisations in April. It focused on whether blockchain-based digital currency could be connected as a new means of payment and settlement while maintaining the existing public payment infrastructure.

The two organisations built a local gift certificate test environment separated from actual services. They implemented the full process in which users topped up gift certificate tokens with blockchain-based digital currency, made payments and had funds settled to merchants.

The blockchain infrastructure used Optimism, an Ethereum layer2 ecosystem. Layer2 is a technology that improves blockchain processing speed and reduces costs by handling transactions outside Ethereum and then recording the results.

Toss verified a structure that links digital currency transfer records written to the blockchain with transaction information in the existing payment system.

It also tested a transaction information protection function. To reduce the risk that payment-related information could be exposed externally on a public blockchain, it applied a privacy solution called Privacy Boost.

The PoC also implemented a structure in which payment and merchant settlement are handled as a single transaction process and merchants can transfer funds at a time of their choosing. It said that if applied to real services in the future, it could be used to shorten processing time and lower related costs in existing payment and settlement processes.

A Toss official said, "As public payment infrastructure is a service used every day, stability and personal information protection must come first," and added, "We will continue to verify payment and settlement infrastructure that can ease the burden on small business owners."

Separately, Toss will fully subsidise Toss Pay payment fees for small online merchants from Sept. 21 to 27 over the Chuseok holiday.

The support applies to payments made using Toss Pay Money or bank accounts at small online merchants. It will be applied automatically without a separate application, and fees incurred during the period will be refunded in early October. Toss said its holiday fee support for small merchants is the second such move, following a similar programme during the Lunar New Year.