Secret Sharing Scheme for Data Confidentiality Preserving in a Public-Private Hybrid Cloud Storage Approach

Adopting public cloud services implies a loose of control in the management process of the outsourced infrastructure. This raises legal and trust concerns among executives and decision factors regarding confidentiality of data being moved in cloud. We propose a protocol based on a secret sharing scheme in which data is split in optimal chunks, each chunk carrying a minimum informational content relative to the entire informational content of the data set. The file chunks are stored in multiple cloud storage volumes in a way that minimizes the probability for an insider or an attacker to reconstruct the original data set. The splitting heuristic is based on Kullback-Leibler as a metric of chunk optimality while the chunk distribution strategy uses a probabilistic model.