Design And Implementation Of Searchable Public Key Encryption For Cloud Storage

With the rapid development of cloud storage, in order to save the local storage and computing resources, individuals and even enterprises are inclined to employ semi-trusted cloud servers to store vast data. For the sake of confidentiality, the data is usually encrypted and then stored in the cloud servers. However, it is rather difficult to search data when it is encrypted. To resolve this problem, this paper studies the problem of how to use the searchable public key encryption technology to search keywords in the encrypted data when it is stored in cloud. First, this paper reviews three representative searchable public key encryption schemes, and then explains that Lai’s scheme gains advantage over other two schemes. However, Lai’s scheme merely focuses on the encryption of keyword, not on the actual data encryption. In addition, Lai’s scheme relies on the composite order bilinear pairing group. However, there is no implementation of searchable public key encryption in the composite order bilinear pairing.Therefore, in this paper, we first propose an improved scheme, which supports the encryption of both the keywords and the actual data. Since our improved scheme also uses the composite order bilinear pairing group, we implement the improved scheme, and present the efficiency comparions. Finally, this paper analyzes the functionality requirements of the scheme when it is employed in the real application, present an application model, and employ our proposed scheme in this application model.