Turn on encryption on your Android Jelly Bean device
Use encryption to protect your Android device's data
Here's how you can turn on encryption on your Android Jelly Bean device.
1. Go to Settings.
2. Go to Encryption.
3. Click the Encrypt button to encrypt your data.
Encrypting your data make take an hour or more, and you should have your Android device plugged in while the encrypting is happening. Do not interrupt the encryption process or you might lose some or all of your data.
For more, see the original article at the link below.
50 Android Jelly Bean tips, tricks and hints | Tech Radar