Secure and Private Information Retrieval (SAPIR) in Cloud Storage Systems

An information theoretic approach to security and privacy for cloud data storage systems is introduced in this paper. The approach called Secure and Private Information Retrieval (SAPIR) is a random combination of all contents that are stored across the network by using Random Linear Fountain codes. SAPIR achieves asymptotic perfect secrecy. To retrieve a content, a group of servers collaborate with each other to form a Repair Group. Further, an information theoretic Private Information Retrieval scheme based on random queries is proposed that ensures that a user privately downloads its desired content without the servers knowing the requested content index. The proposed scheme is adaptive and can provide privacy against a significant number of colluding servers.