The tension level at the grocery store checkout sometimes rises when a customer needs extra time because they have no cash and therefore have to pay with a bank card.

This is especially true in Germany where there is almost always a line at the cash register and it’s standard for customers to have to bag their own groceries.

Some supermarkets in the country are working to remedy this problem by using a fingerprint scanner to verify identity and make the electronic payment.

A pilot project at a supermarket in the Rewe chain is under way near Cologne to test the viability of implementing the payment method in all Rewe affiliates in Germany. The comprehensive affiliate biometric payment method, as it is called, has a “handy” advantage, said cashier Helga Gerth.

“Cash can be forgotten, a bank card can be lost, but a finger can’t,” she said. The new payment method is being accepted positively by people of all ages. The people who shop at the store are the guinea pigs for the test, said a spokeswoman for North Rhine-Westphalia’s data protection office.

Fingerprint payment systems already are in use in some supermarkets in Germany, said Ulrich Binneboessel of the association of German retailers, but until now only in isolated applications.

“Some one hundred markets belonging to the Edeka chain in southern Germany thus far have implemented the payment method,” said Binneboessel, explaining that it was limited to independent stores.

The Duesseldorf-based retailer Metro is also testing the technology in Future Store, which is part of its Real grocery store chain, in Toenisvorst near Duesseldorf.

The fingerprint payment method being tested at the Rewe chain is designed to make cashless and cardless payment possible in participating grocery stores. The Hamburg company Dermalog, which specializes in biometrics, provides the technology. It plans to formally introduce its system at the computer trade show CeBIT in March. It wants to help get the idea of fingerprint payment accepted across Germany.

At Rewe customers have to register at a terminal in the store by putting one finger from the right hand and one from the left on a scanner and inputting their address and bank account numbers. This enables the system to deduct the amount spent from the proper bank account.

“We want to test the technology’s suitability for daily use and its acceptance level among customers,” said Rewe spokesman Andreas Kraemer. Because only some characteristics of the fingerprint are scanned and converted into an anonymous numeric code, the entire fingerprint cannot be reconstructed. Rewe stores the data in highly secure databases separate from other personal and account data it collects.

“The process is secure,” Kraemer said. “The scanner at the cash register can recognize whether a finger is real or not - it tests the blood circulation in the finger. You can’t use a dummy finger or a fingerprint lifted with sticky tape a la James Bond.” However, members of Chaos Computer Club recently did something similar. They took a fingerprint from a glass that a customer had held and copied it. They were then able to use the copy to delude the scanner. Nevertheless, the retailers’ association considers the technology secure.

“This is an interesting system for the future with a high security standard. There will never be a system that is 100 per cent secure,” Binneboessel said, adding that using a fingerprint payment method is as secure as using a PIN.

Bettina Geyk, spokeswoman for the North Rhine-Westphalia data protection office, said employees of the office were unsuccessful when they tried to dupe the scanner.

“As long as the fingerprint is just an optional payment method, the participants are completely informed and also know that a central database is behind the system, it is legally acceptable,” she said.

But you have to be conservative in deploying it. The fingerprint is not universally accepted as a payment method. If it were to replace other payment systems, there would be a database with the data of practically all citizens stored in it. This would require a basis in law.

Geyk also noted that central databases pose a problem because they are easier targets for hackers.

People who support the biometric system always include the time factor in arguing for the system.

“On average paying using a fingerprint takes only seven seconds, paying with a bank card that requires a PIN takes 12 seconds and paying with cash takes 20,” said Kraemer. Three hundred people have been participating in the pilot project since it went into place three months ago. They use the payment method regularly.

One tester, a 28-year-old man, said it was “super” and above all else convenient. But his girlfriend dismissed it. “As long as I cannot see through the system and don’t know who can get access to my data, I won’t go along with it,” she said.

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