Computer Science Department
School of Computer Science, Carnegie Mellon University
On Consistency of Encrypted Files
Alina Oprea, Michael K. Reiter
We first formally define consistency for encrypted file objects in a generic way: for any consistency conditions for the key and file objects belonging to one of the two classes of consistency conditions considered, we define a corresponding consistency condition for encrypted file objects. We then provide, in our main result, necessary and sufficient conditions for the consistency of the key distribution and file storage protocols under which the encrypted storage is consistent. Lastly, we give an example implementation of a consistent encrypted file object, utilizing a fork consistent file access protocol and a sequentially consistent key distribution protocol. The proof of consistency of the implementation builds from our main theorem.