Efficient and Secure Remote Data Storing and Processing Mohd Rizuan Baharon, Qi Shi, David Llewellyn‐Jones and Madjid Merabti School of Computing and Mathematical Sciences, Liverpool John Moores University, UK
[email protected] [email protected] D.Llewellyn‐
[email protected] [email protected] Abstract: Storing and processing data remotely is becoming a popular trend for people to deal with their data in order to overcome storage spaces and computing resources limitation. However, moving private data to untrusted third parties like clouds with limited digital control by data owners raises security concerns. Primitive encryption schemes seem ineffective to be used as such techniques require encrypted data need to be decrypted first before data can be processed. Thus, homomorphic encryption is believed to be one of the potential solutions as it allows arbitrary computation on encrypted data without decryption process. The first fully homomorphic encryption (FHE) scheme was introduced by Gentry, then followed by other researchers that produced similar and complex schemes like Gentry’s one. Such schemes are suffering from poor efficiency as too much noise is produced by the process on encrypted data. Thus, this research work will deeply look at efficiency issue and propose a new scheme which minimizes the use of noise at the processing stage. The scheme implements the Elliptic Curve (EC) group as the underlying group since EC promises efficiency and strong security. The use of n‐multilinear map along with the construction of the scheme is to enable the achievement of a FHE scheme. The key contribution of this work is to propose a FHE scheme with improved efficiency. Furthermore, an improve security of a Secure Sockets Layer protocol will be the second contribution as the used of the proposed FHE scheme enables data to be transmitted and processed securely and efficiently. Keywords: cloud computing, data storage, homomorphic encryption, elliptic curve, n‐multilinear map, secure sockets layer (SSL)
1. Introduction Cloud Computing is becoming a popular IT technology that has changed the way people use IT technologies to run their businesses. This is due to cloud providing huge data storage and powerful computing resources to their clients who have less capability to store and process their data internally. Those benefits can be accessed with minimum requirements like desktop machines and Internet connection. As clouds provide services on a pay‐as‐you‐use basis, it enables their clients to leverage their services based on client’s needs. However, clients are still reluctant to adopt such a technology due to security concerns on their data (Subashini & Kavitha 2011). Thus, research on securing data and their related processing by cloud‐based applications is getting more attention from academia as well as enterprises working on or using cloud services. Clients, who are interested to use cloud services effectively, need to outsource their data to Cloud Service Providers (CSPs). However, outsourcing sensitive data into clouds with no physical and limited digital control by the clients raises serious concerns about data security. Due to the scale, dynamicity, openness and resource‐sharing nature of cloud computing, addressing security issues in such environments is a very challenging problem (Zissis & Lekkas 2012). To ensure privacy and integrity of the data is preserved, encryption techniques should be implemented. Primitive encryption schemes seem ineffective to be implemented in such an environment because the encrypted data cannot be processed without decryption (Mahmood 2011). Thus, a scheme that allows data to be processed in encrypted form like a FHE scheme is needed. However, existing FHE schemes are suffering from efficiency issues as they are computationally expensive. Ciphertexts generated through those schemes are “noisy” (Fan & Vercauteren 2012). Such limitations require an improved FHE scheme to be proposed. Thus, we propose a new FHE scheme based on a finite field that supports an n‐multilinear map in this paper. The scheme is constructed based on an open problem raises by Boneh et al. (Boneh 2005), on their previous work on a bilinear map. Our scheme will be executed using SSL protocol to achieve high security between clients and cloud providers. SSL is developed by Netscape (Chou 2002) providing a secure communication channel and mechanisms between two parties (a client and a server). The goals for SSL not only include security, but also
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