A Chinese state-backed institution has devised a way to identify users who send messages via Apple Inc.’s popular AirDrop feature, Beijing’s government claims, as part of broader efforts to root out undesirable content.The Beijing institute developed the technique to crack an iPhone’s encrypted device log to identify the numbers and emails of senders who share AirDrop content, the city’s judicial bureau said in an online post. Police have identified multiple suspects via that method, the agency ...