http://androidforums.com/samsung-droid-charge/370428-security-storage-process.html
A quick Google search reveals:
December 12th, 2012, 07:55 PM #7 (permalink)
Default android.providers.internal.security
Cilraaz is right. It is a core service that comes on some newer Android phones from some providers, but not all, and that it is designed to speed things up and handle secure read and writes. It helps keep rogue apps from accessing personal data in the phone. It has access to about everything along with a couple of other service processes. It came on my Galaxy SIII. Other configurations of the SIII handle this in other ways. It doesn't have much effect on battery life on the Galaxy. It is best to not disable it if it is on there and don't worry about it if it is not.