Japan-based tech conglomerate Hitachi and telecommunication giant KDDI are testing a blockchain-based system that can settle retail payments using shoppers’ fingers.

According to a release on Wednesday, a group of staff from the two partners are this week experimenting with a coupon settlement system deployed in a KDDI store in Tokyo’s Shinjuku district, as well as a local donut shop.

Built by Hitachi with technology from the Hyperledger Fabric platform, the blockchain system is integrated with Hitachi’s biometric verification and KDDI’s existing coupon system. It seeks to settle shoppers’ coupon transactions over a distributed network based on the vein pattern of their fingers as validators.

Hitachi explained that when shoppers sign up to use the system, they will register their coupon credits and biometric information, which are then encoded into a string of encrypted data and stored on the blockchain.

When initiating a transaction at a retail shop that accepts the coupons and participates in the blockchain as a node, shoppers will verify their identity with a finger reading device that broadcasts the request to the network and the transaction is settled.

Hitachi said the end goal is to use a tamper-proof blockchain to assist in verifying the vein pattern of users’ fingers and to keep their coupon usage information accurate and updated across stores within the network simultaneously.

“As a result, users can authenticate themselves by holding the finger on the authentication infrastructure, so it is not necessary to present a coupon at the store, and the coupon can be used even without a smartphone,” the company said in the release.

The project is the latest pilot test taken by Hitachi to utilize a blockchain platform in retail transactions. Last year, the company also announced it is developing a blockchain platform for supply chain businesses to manage orders and invoices on an immutable ledger.

Hitachi image via Shutterstock