Part of keeping your device secure is making sure that if it is lost or stolen, other people cannot access your data. Both IOS and Android have built-in device encryption which renders the data on the device useless if the password is unknown.
- To encrypt an iPhone or iPad (3GS or later):
- Touch Settings, this should take you into the General settings area.
- Touch the Turn Passcode On button
- Type in your passcode (a 4 digit code) and repeat when prompted
- Slide Siri to the off position when device is locked (otherwise Siri can bypass your locked device)
- Slide Erase Data to the on postion (this will wipe your device if someone tries guessing your code over and over.
- You will see at the bottom of the screen that "Data protection is enabled"
This method of encryption can be toggled on or off depending if you use a password or not - once enabled you'll need to enter your passcode when you want to access these settings.
This is a good article which speaks to the security that is provided by enabling this feature on an iPhone or iPad: http://www.technologyreview.com/news/428477/the-iphone-has-passed-a-key-security-threshold/