A Spy in Our Pocket

Mobile Handset Privacy: Measuring The Data iOSand Android Send to Apple And Google

Douglas J. Leith

School of Computer Science & Statistics,

Trinity College Dublin, Ireland

25thMarch, 2021

Abstract—We investigate what data iOS on an iPhone shareswith Apple and what data Google Android on a Pixel phoneshares with Google. We find that even when minimally configuredand the handset is idle both iOS and Google Android sharedata with Apple/Google on average every 4.5 mins. The phoneIMEI, hardware serial number, SIM serial number and IMSI,handset phone number etc are shared with Apple and Google.Both iOS and Google Android transmit telemetry, despite theuser explicitly opting out of this. When a SIM is inserted bothiOS and Google Android send details to Apple/Google. iOS sendsthe MAC addresses of nearby devices, e.g. other handsets andthe home gateway, to Apple together with their GPS location.Users have no opt out from this and currently there are few, ifany, realistic options for preventing this data sharing.