Transparent, Distributed, and Replicated Dynamic Provable Data Possession

With the growing trend toward using outsourced storage, the problem of efficiently checking and proving data integrity needs more consideration. Starting with PDP and POR schemes, many cryptography and security researchers have addressed the problem. After the first solutions for static data, dynamic versions were developed (e.g., DPDP). Researchers also considered distributed versions of such schemes. Alas, in all such distributed schemes, the client needs to be aware of the structure of the cloud, and possibly pre-process the file accordingly, even though the security guarantees in the real world are not improved.

We propose a distributed and replicated DPDP which is transparent from the client’s viewpoint. It allows for real scenarios where the cloud storage provider (CSP) may hide its internal structure from the client, flexibly manage its resources, while still providing provable service to the client. The CSP decides on how many and which servers will store the data. Since the load is distributed, we observe one-to-two orders of magnitude better performance in our tests, while availability and reliability are also improved via replication. In addition, we use persistent rank-based authenticated skip lists to create centralized and distributed variants of a dynamic version control system with optimal complexity.