At the Google I/O 2014 keynote, Sundar Pichai took to the stage to let us know that the L release of Android is set to make massive improvements in security for the enterprise as well as regular users. The Washington Post has received word from Google that gives us another glimpse of what we should expect in the next version. It seems that devices shipping with Android L will have disk encryption enabled by default. The move is pegged as a step to prevent law enforcement officers from obtaining information from phones and tablets without an owner's consent. Apple just made the same change in iOS 8, released earlier today.
This change will allow Google and other manufacturers to avoid legal and ethical questions arising from search warrants issued against phones and tablets. Since they will not have the ability to provide tools that can be used to access secured data on a device, they can't be compelled to do so. Automatic encryption will go a long way to protect devices from unauthorized access by law enforcement and hackers, but it will have no impact on data that is stored in the cloud, which can still be targeted by a court order.
Full-disk encryption has been available on Android since 2011, but it was not enabled by default and users are never prompted to turn it on during setup. The implementation of full-disk encryption is very efficient, so there should be no implications to performance and battery life. While new devices equipped with Android L are going to ship with encryption turned on, it's not yet clear if existing hardware will be encrypted automatically after being updated from an older version of the operating system.
Source: Washington Post