Handoff is part of Continuity, which is designed to make iPhones, iPads, and Macs work together more quickly, easily, and seamlessly than ever before. Rather than putting the same interface across all their devices, or making the web the center of the universe, Handoff is keeping things personal. Devices have to be logged into your Apple ID. You have to be within Bluetooth Low Energy (BT LE) proximity. And instead of automatically pushing your data out, Handoff waits for you to elect to use it. That all makes it private, but what makes it secure?
Full story from the iMore Blog...