Towards Secure and Effective Utilization over Encrypted Cloud Data

Abstract

Cloud computing enables an economic paradigm of data service outsourcing, where individuals and enterprise customers can avoid committing large capital outlays in the purchase and management of both software and hardware and the operational overhead therein. Despite the tremendous benefits, outsourcing data management to the commercial public cloud is also depriving customers' direct control over the systems that manage their data, raising security and privacy as the primary obstacles to the adoption of cloud. Although data encryption helps protecting data confidentiality, it also obsoletes the traditional data utilization service based on plain text keyword search. Thus, enabling an encrypted cloud data search service with privacy-assurance is of paramount importance. Considering the large number of data users and huge amount of outsourced data files in cloud, this problem is particularly challenging as it is extremely difficult to meet also the practical requirements of performance, system usability, and high-level user searching experiences. This paper investigates these challenges and defines the problem of fuzzy keyword search over encrypted cloud data, which should be explored for effective data utilization in Cloud Computing. Fuzzy keyword search aims at accommodating various typos and representation inconsistencies in different user searching input for acceptable system usability and overall user searching experience, while protecting keyword privacy. In order to further enrich the spectrum of secure cloud data utilization services, we also study how the notion of fuzzy search naturally supports similarity search, a fundamental and powerful tool that is widely used in information retrieval. We describe the challenges that are not yet met by existing searchable encryption techniques and discuss the research directions and possible technical approaches for these new search functionalities to become a reality. The investigation of the proposed research can become the key for cloud service providers to securely and effectively deliver value from the cloud infrastructure to their enterprise and individual customers, and thus significantly encourage the adoption of Cloud Computing in a large scale.