authentication

The unique serial number on the bank note was the authentication he needed to ensure he was handing the cash over to the right person.

“Multi-factor authentication attacks have been happening for well over a decade,” Manky said.

Some included images of women holding photo identification for verification purposes, which Tea's own privacy policy promises are "deleted immediately" after authentication.

Age verification firm Verifymy says when you carry out this check on its service, a two-factor authentication check and a mini transaction with no exchange of money takes place, similar to checking into a hotel.

Its investigation - launched along with Canada's privacy commissioner last June - found that 23andMe breached UK data protection law by not having appropriate authentication and verification measures for customers during its login process.