The math, physics, and general computer security make it impossible to decrypt a device without some kind of key or alterations to the operating system. The same tech preventing the FBI from reading a drug dealers’s text messages is the same tech protecting everyone else from hackers, and even protecting freedom advocates from oppressive regimes. Any compromise for law enforcement unfortunately creates exploitable holes for bad actors.
http://bgr.com/2017/05/04/mobile-security-fbi-smartphone-encryption/