Using All-or-Nothing Encryption to Enhance the Security of Searchable Encryption
Wenqi Ma, Qingbo Wu, Yusong Tan, Chunguang Wang, Quanyuan Wu, Huaping Hu · 2013
Outsourcing data to cloud servers is a trend in the development of the computer. Encrypting the data while maintain the search ability of it is an important technology for cloud storage. Many works on the searchable encryption focus on how to securely search over encrypted data but ignore the security of the encryption. In searchable encryption, the words must be encrypted separately. The encryption function in many searchable encryption schemes is a deterministic algorithm. These characteristics bring security defects to the encryption. In this paper, we encrypt the documents into n pieces with a secret sharing algorithm and disperse them to different clouds. Each piece will reveal no information about the document. But the attacker can get all pieces through intercept the communication between the client and the cloud. For solving this problem, we encrypt one or more of pieces with an all-or-nothing encryption (AONE). The AONE can increases the time for brute force. Attacker who wants to crack any one encrypt word must crack the encrypted piece firstly. Our scheme also has some problems. Encrypting some pieces with the AONE will bring some errors to the search result. We will prove the error probability is low when we choose the reasonable parameters.