We know that Apple has investigated into various security methods for iOS devices in the past, one of which resulted in Find my iPhone that allows users to track their missing/stolen iPhones remotely. Now it seems that in a recently discovered patent, it looks like Apple is investigating a way to make use of the built-in accelerometer and a specialized controller to detect when a device has been stolen, or when “theft condition is present”. Based on description of the patent, this particular security feature seems to deal with situations such as mugging or snatch theft when the phone is roughly taken out of the hands of its owner.
According to the patent, they have described “theft conditions” which are likely to involve large-scale movement, such as carrying the device in the hand which will then generate low-frequency acceleration signals. So by instituting a low-pass filter, those low-frequency acceleration signals can then be associated with probable theft conditions which at the same time helps reduce false alarms. At the same time users can adjust the sensitivity of the detection, along with the alarm they wish to have go off when the device has been taken and etc. There will also be a delay between the time the phone detects a theft, which allows the user to enter a passcode to deactivate the alarm.
Of course we expect that there will need to be quite a bit of fine tuning involved to ensure false alarms don’t go off simply by having our phones in our pockets and walking, but it sounds like a pretty legit system especially in snatch theft scenarios where the phone’s constant alarm will help the authorities locate the device.