The anti-snoop Blackphone
4 March 2014 Last updated at 13:28 GMT
Revelations by US whistleblower Edward Snowden have put privacy and data security high on the agenda.
BBC Click's Jennifer Copestake looks at a new smartphone which offers encrypted text messages and calls and allows you to control what information the phone transmits wirelessly as you move around.
But is the Blackphone, made by Silent Circle, secure enough to stop the US National Security Agency getting access to your data?