my sony experia won't start up

[Android Question]

I have encryption software on my sony experia for work. I flew on a plane today and upon arrival at my destination I turned off the airplane mode. I could not get a signal therefore turned the phone off. When i turned it back on i got my encryption screen and typed in the password. It cycled thru start up and then the encryption screen came back on. This continues to repeat every time i try to start the phone. i cannot get past this no matter what i try and cannot get the phone to start. It just continues to re-cycle start up and back to the encryption screen requesting my password.