Deduplication-Friendly Watermarking for Multimedia Data in Public Clouds.

To store large volumes of cloud data, cloud storage providers (CSPs) use deduplication, by which if data from multiple owners are identical, only one unique copy will be stored. Deduplication can achieve significant storage saving, benefiting both CSPs and data owners. However, for ownership protection, data owners may choose to transform their outsourced multimedia data to “protected formats” (e.g., by watermarking) which disturbs deduplication since identical data may be transformed differently by different data owners.