Auditable Versioned Data Storage Outsourcing

TL;DR

This paper introduces a novel auditable, versioned data storage scheme that efficiently supports dynamic, multi-version data verification with minimal overhead, enhancing accountability in outsourced data management.

Contribution

It presents algorithms for full persistence in an optimized skip list, enabling efficient auditing of all data versions with deduplication and minimal performance impact.

Findings

Supports auditing of all data versions with negligible overhead.

Achieves deduplication at the block level for storage efficiency.

Commit operations incur only about 5% additional time.

Abstract

Auditability is crucial for data outsourcing, facilitating accountability and identifying data loss or corruption incidents in a timely manner, reducing in turn the risks from such losses. In recent years, in synch with the growing trend of outsourcing, a lot of progress has been made in designing probabilistic (for efficiency) provable data possession (PDP) schemes. However, even the recent and advanced PDP solutions that do deal with dynamic data, do so in a limited manner, and for only the latest version of the data. A naive solution treating different versions in isolation would work, but leads to tremendous overheads, and is undesirable. In this paper, we present algorithms to achieve full persistence (all intermediate configurations are preserved and are modifiable) for an optimized skip list (known as FlexList) so that versioned data can be audited. The proposed scheme provides deduplication at the level of logical, variable sized blocks, such that only the altered parts of the different versions are kept, while the persistent data-structure facilitates access (read) of any arbitrary version with the same storage and process efficiency that state-of-the-art dynamic PDP solutions provide for only the current version, while commit (write) operations incur around 5% additional time. Furthermore, the time overhead for auditing arbitrary versions in addition to the latest version is imperceptible even on a low-end server...