Implementation of searchable symmetric encryption for privacy-preserving keyword search on cloud storage

Swee-Huay Heng,Wun-She Yap,Ji-Jian Chin,Syh-Yuan Tan,Wei-Chuen Yau,Huo-Chong Ling,Md Iftekhar Salam,Raphael C-W Phan,Geong Sen Poh

doi:10.1186/s13673-015-0039-9

Abstract

AbstractEnsuring the cloud data security is a major concern for corporate cloud subscribers and in some cases for the private cloud users. Confidentiality of the stored data can be managed by encrypting the data at the client side before outsourcing it to the remote cloud storage server. However, once the data is encrypted, it will limit server’s capability for keyword search since the data is encrypted and server simply cannot make a plaintext keyword search on encrypted data. But again we need the keyword search functionality for efficient retrieval of data. To maintain user’s data confidentiality, the keyword search functionality should be able to perform over encrypted cloud data and additionally it should not leak any information about the searched keyword or the retrieved document. This is known as privacy preserving keyword search. This paper aims to study privacy preserving keyword search over encrypted cloud data. Also, we present our implementation of a privacy preserving data storage and retrieval system in cloud computing. For our implementation, we have chosen one of the symmetric key primitives due to its efficiency in mobile environments. The implemented scheme enables a user to store data securely in the cloud by encrypting it before outsourcing and also provides user capability to search over the encrypted data without revealing any information about the data or the query.

Highlights

With the rapid development of cloud computing and mobile networking technologies, users tend to access their stored data from the remote cloud storage with mobile devices
The main advantage of cloud storage is its ubiquitous user accessibility and its virtually unlimited data storage capabilities. Despite such benefits provided by the cloud, the major challenge that remains is the concern over the confidentiality and privacy of data while adopting the cloud storage services [1]
Unencrypted user data stored at the remote cloud server can be vulnerable to external attacks initiated by unauthorized outsiders and internal attacks initiated by the untrustworthy cloud service providers (CSPs) [2]

Summary

Background

With the rapid development of cloud computing and mobile networking technologies, users tend to access their stored data from the remote cloud storage with mobile devices. The naïve approach for retrieving encrypted contents related to a certain keyword would require the user to download all the stored data, and decrypt and perform the search on the local machine. To provide a secure and efficient retrieval of data, one needs to ensure that the user can perform a search over the encrypted data without revealing the contents and the searched keyword to the server. This research aims to study the searchable encryption schemes in detail and implements a solution that enables privacy preserving data storage and retrieval system in cloud computing (aka PrivCloud). To enable the privacy preserving keyword search, this scheme will generate an encrypted keyword index which will be outsourced to the cloud server along with the encrypted data set. A brief description of the entities and their operations are given below

Data owner

Document re-processing

D2 D3 D4 D5

Encryption

Key generation class

Decryption class

Conclusion