Auditor and professional services firm KPMG has warned that the use of stealth "black phones," like the recently unveiled Boeing Black, may make people a bigger target for hackers.

Stephen Bonner, partner at the Information Protection and Business Resilience team at KPMG, argued that the fact that the so-called "black phones" will attract privacy-sensitive customers who want to hide below the radar will make these devices an appealing target.

He said that owning a device like the Boeing Black would act as a "red flag" to criminals, highlighting that there is something to hide, and thus an opportunity to obtain potentially sensitive and lucrative information.

Of course, since these devices are by default more secure they should, at least in theory, be difficult nuts to crack.

Security is the new black

KPMG's warning follows the recent announcements of the GeeksPhone Blackphone and the Boeing Black. The latter is an Android-based device designed specifically for enhanced security.

It includes embedded hardware security features, including a secure boot option, disk encryption, protected communications, and options for various modules like satellite transceivers, solar-powered chargers, and biometrics.

The move puts Boeing, known for its aircraft and defence contracts, into direct competition with the original "black phone" manufacturer, BlackBerry. The Canadian firm has etched out a living from the business and government sectors, thanks to its security-focused approach, but consumer firms like Apple and Samsung have attempted to eat into its market share.

However, Bonner said that privacy should not be limited to handsets for people who have something to hide, but should be default for all.

"The ability to keep data safe and secure without having to think about it should feature in all devices so that all calls, messages, files and browsing data is kept private. 'Black phones' could be the start of a new trend for all phones becoming more secure," he said.

He dismissed the use of such devices for the consumer market, calling some of the threats they aim to protect against unrealistic. He said that business users need to worry about the applications on their devices and the end-to-end protections they have in place.