See https://developer.apple.com/library/ios/documentation/security/Conceptual/keychainServConcepts/01introduction/introduction.html#//apple_ref/doc/uid/TP30000897 /cc @toddmurphy
See https://developer.apple.com/library/ios/documentation/security/Conceptual/keychainServConcepts/01introduction/introduction.html#//apple_ref/doc/uid/TP30000897
/cc @toddmurphy