HSBC is using an improved digital-validation certificate in an attempt to protect its customers against online fraud.

Under the VeriSign-supplied extended validation (EV) SSL authentication marker, the address bar of web browsers turns green when the site visited is legitimate.

"The certificates will allow us to send an instantly recognisable signal – the reassuring green bar – to our online banking customers," said Barry Jones, HSBC’s senior manager for group IT security.

“It confirms that any personal information they supply on that page will go directly to HSBC and no one else,” he said.

The system works in PC versions of browsers such as Microsoft Internet Explorer and Mozilla Firefox, but it does not work for Mac-based software.