How picking up your smartphone could reveal your identity

The time a person spends on different smartphone apps is enough to identify them from a larger group in more than one in three cases say researchers, who warn of the implications for security and privacy. They fed 4,680 days of app usage data into statistical models. Each of these days was paired with one of the 780 users, such that the models learnt people's daily app use patterns. The researchers then tested whether models could identify an individual when provided with only a single day of smartphone activity that was anonymous and not yet paired with a user. Software granted access to a smartphone's standard activity logging could render a reasonable prediction about a user's identity even when they were logged out of their account. An identification is possible with no monitoring of conversations or behaviors within apps themselves.