MIDN 1/C John M. Hanling - 8th Company
Proofs of Retrievability with Low Server Storage
Adviser: Associate Professor Daniel S. Roche, Computer Science DepartmentExternal Collaborators: Mr. Gaspard Anthoine, Professor Jean-Guillaume Dumas, Associate Professor Aude Maignan, Associate Professor Clément Pernet, Université Grenoble Alpes
Major: Computer Science
Description:
We investigate a novel approach to Proofs of Retrievability (PoR), protocols that allow a client to audit the cloud server storing its data remotely. Past PoR approaches have worked toward computational optimization for the audit; however, this requires a large amount of overhead persistent storage (up to 10x the actual database size). Our new approach instead trades higher computation for significantly decreased persistent storage. As all major cloud providers charge markedly more for storage than for computation, our new protocol offers practical efficiency. Our approach rests on treating the data as a square matrix, comparing randomized linear algebra identity tests over the matrix at the time of last check and at the current time. While audit computation becomes linear, the required persistent storage is only 1.09x the size of the database. We demonstrate its efficiency in practice with a deployment on Google Cloud Platform, and see that, for example, auditing a 1 TB data file takes 16 minutes at monetary cost of $0.23 USD. This remains monetarily beneficial to other PoRs that have even 2x persistent storage if audits are performed every five hours.