Identity fraud is big business and now hackers are tapping in to voice-over IP telephony accounts, say a VoIP equipment maker.

Newport Networks have found that Usernames and Passwords from voice-over IP (VoIP) phone accounts are selling online for more than stolen credit cards.

The information allows someone to use the telephone service for free but net telephony fraud is still at an early stage, with eavesdropping on calls being the most common form.

Dave Gladwin, vice president of products at Newport Networks thinks the move into stealing usernames and passwords which are routinely sent across the network when a call is made, is a worrying new trend

“It is still at an embryonic stage but as voice adoption increases it becomes more of a problem and needs addressing,” said Mr Gladwin.

The details are not sent as plain text but are encoded in such a way as to be “easily captured and un-obscured”, said Mr Gladwin.

You can, quite worryingly, buy credit card details easily online for around £6 ($12) but VoIP details come at a higher price – around £9 ($17), according to Mr Gladwin.

The problem not as large an issue for businesses which routinely offer voice-over IP services for their employees because users are tied into a secure corporate network, but for consumers, relying on public or unsecured home wi-fi networks, there is more of an issue.

“90% of carriers don’t offer a secure VoIP service,” said Mr Gladwin.

He estimated it would cost around £2/£3 per subscriber for service providers to instigate the additional level of security needed.

“Most of the software out there has the capability of running in secure mode if the service providers would accept it,” he said.

Jonathan Christensen, general manager of audio and video at Skype said, “It doesn’t matter whether I’m on an open wireless connection, there is no way someone could get hold of my username or password,” because Skype’s service, unlike some of its rivals, offers end to end encryption.

He accepts there are security issues facing the industry, especially for providers that use “less robust security mechanisms” but he questions how big a draw a free VoIP account would be for net criminals.

This is a view shared by Jupiter analyst Ian Fogg.

“I have not seen security issues with VoIP as a big issue. This is partly because such services aren’t that mainstream and therefore have not been targeted by criminals in the way that e-mail and online banking services have,” he said.