SPARK: Secure Pseudorandom Key-based Encryption for Deduplicated Storage

Deduplication is a widely used technology to reduce the storage and communication cost for cloud storage services. For any cloud infrastructure, data confidentiality is one of the primary concerns. Data confidentiality can be achieved via user-side encryption. However, conventional encryption mechanism is at odds with deduplication. Developing a user-side encryption mechanism with deduplication is a vital research topic. Existing state-of-the-art solutions in security of deduplication are vulnerable to dictionary attacks and tag inconsistency anomaly. In this paper, we present SPARK, a novel approach for secure pseudorandom key-based encryption for deduplicated storage. SPARK achieves semantic security along with deduplication. Security analysis proves that SPARK is secure against dictionary attacks and tag inconsistency anomaly. As a proof of concept, we implement SPARK in realistic environment and demonstrate its efficiency and effectiveness.