The Communications-Electronics Security Group (CESG), the group within the UK Government Communications Headquarters (GCHQ) that assesses operating systems and software for security issues, has found that while no end-user operating system is as secure as they’d like it to be, Ubuntu 12.04 is the best of the lot.
In late 2013, the CESG looked at the security of the most popular end-user operating systems for desktops, smartphones, and tablets [PDF Link]. This included: Android 4.2, Android 4.2 on Samsung devices; iOS 6, Blackberry 10.1, Google’s Chrome OS 26, Ubuntu 12.04, Windows 7 and 8; Windows 8 RT, and Windows Phone 8. These were judged for their security suitability for OFFICIAL level use according to the UK Government Security Classifications (PDF Link). This is the UK’s government lowest security level.