How do I update my encrypted phone (CyanogenMod 12)? I want to encrypt my phone(Xperia M). It has CyanogenMod 12 with cyanogenmod recovery. Wanted to know if I could update it the normal way, flashing through recovery, or some other way.
As of 04-01-2015 custom recoveries don't support decryption CM12 yet. It will give you a wrong password notification when trying to decrypt.  

But you can put the update.zip in /cache partition. Then in the recovery, skip entering the password. And flash from /cache partition. 
This works because you don't need your password to access /cache partition.