A new way of accessing bank accounts is being launched which identifies individuals through the unique pattern of veins in their fingers.
Instead of having to use a series of passwords and numbers, users will be able to log on to their accounts by placing one of their fingers into a scanner.
The technology is quite distinct from fingerprint recognition.
To begin with, Barclays will offer the service to business customers only.
However, "finger vein authentication", as it is known, is likely to be offered to all customers in the future.
A portable scanner, the size of a tennis ball, is plugged into the computer's USB port and uses near-infra-red light to check the unique pattern of veins inside the finger.
Only a living finger is accepted by the scanner, reducing the risk that fraudsters will use substitutes or copies to break into a bank account.
Banks are casting around for new ways to combat fraud, as users become increasingly fed up with multiple passwords and PINs, or having to use electronic number generators whenever they log on.
The new finger vein technique has been pioneered by the Japanese firm Hitachi. It is already installed in cash machines in Japan and Poland, allowing people to withdraw money without using a card or PIN.
Any business adopting the technology can register several fingers from different members of staff, so one person can make a payment and another can approve it.
The unit can be plugged into different computers.
When an attempt is made to log on to the account, the user is invited to "place a finger lightly on the scanner", and is then told "a finger is detected". If approved, access is allowed within seconds.
Barclays says the technology is relatively expensive at the moment. It will charge business customers for the convenience of having the machines, although it will not reveal the level of fees.
"For corporate clients who do a lot of large transactions, this makes a lot of sense," explained Ashok Vaswani, the bank's head of personal and corporate banking.
He cautions that the scanner is not yet ready for the popular market, where customers are averse to paying extra.
In any case, most ordinary customers prefer to use smartphones to manage their accounts.
"Obviously you can't use such a clunky tool along with mobile banking," said Mr Vaswani.
"I don't think this exact machine is going to be used for retail, but some version of this will definitely come for retail."
Vein recognition is thought to be a more secure technology than checking finger prints, partly because of the requirement for the finger to be "live".
That should also eliminate the grim possibility of a criminal hacking off someone's finger in an attempt to use it to remove funds from an account.
Light transmitted through the finger is partially absorbed by haemoglobin passing through the veins, enabling the unit to authenticate the user's vein pattern.
Hitachi, which has been researching the technology for 15 years, said vein patterns are established in the womb and remain stable for most of a person's life.
But there is some concern that people's biometric information, including vein patterns, might be used or exploited by fraudsters or even government agencies.
Barclays emphasises that the finger details of its customers will be safe. It will not store their details centrally and there will be no public record.
Once the system is up and running next year, the information will be held on a computer chip inside the scanner in encrypted form.
And if engineers can make the scanners smaller and more cheaply, people could start "finger banking" in homes across the UK.