Philip Pullman’s fantasy series His Dark Materials included animal daemons, representative of the owner’s souls. Professor Pamela Briggs and Dr Patrick Olivier have developed an idea where devices (called biometric daemons) can carry a person’s details and replace the need for pin numbers and passwords in everyday life – they would also react differently to levels of risk and eventually die if they are apart from their owner for too long a time period. Voice-recognition technology software that monitors the owner’s actions and movements could also be installed to allow the daemon to become more “intelligent”.

Dr Olivier believes that the idea could be ready within a couple of years "The idea of the daemon is that it is a living credit card," he said. "It would recognise it is with you, and if you put it in your pocket, it can recognise your walk and your voice."

Low-risk transactions would mean that the daemon would not need much "reassurance" to allow the deal to be completed. But if an unknown cash point was used, or if a purchase appeared out of the ordinary, it might require the owner to give a fingerprint before authorisation could be completed.