For more understanding of mobile phone protection, I advise you to read the following:

1. "Android Security Internals: An In-Depth Guide to Android’s Security Architecture” by Nikolay Elenkov
2. "Hacking Exposed Mobile: Security Secrets & Solutions” by Neil Bergman, Mike Stanfield, Jason Rouse, and Joel Scambray
3. "LTE Security” by Dan Forsberg, Günther Horn, Wolf-Dietrech Moeller, and Valtteri Niemi
4. “Mobile Application Security” by Chris Clark, Himanshu Dwivedi, and David Thiel
5. “Mobile Device Security: A Comprehensive Guide to Securing Your Information in a Moving World” by Stephen Fried