A Hybrid Cryptographic Model for Data Storage in Mobile Cloud Computing

Published Online June 2017 in MECS

The ubiquity and increasing capacity of mobile devices have ignited many new computing paradigms such as Mobile Computing, Mobile Cloud Computing, Mobile Sensing, Pervasive Computing, Collaborative Computing and so on. Mobile Cloud Computing (MCC) as one of the paradigms which amalgamated Cloud Computing with Mobile Computing was defined by [2] as “the combination of cloud computing, mobile computing and wireless networks to bring rich computational resources to network operators, mobile users and cloud computing providers”.

MCC inherited different problems from the comprising paradigms. It inherited resource-poverty from Mobile Computing which was solved with Cloud computing.

Meanwhile, Cloud Computing has inherent problems such as security and privacy of user’s data that is stored on cloud, intrusion detection, platform reliability, and security threats caused by multiple virtual machines [12].

In order to mitigate the security and privacy challenges, cryptography has been employed over the years to provide privacy, confidentiality and integrity. Cryptography as one of the major approaches to solving data security issues is defined as  the process of encrypting and decrypting data to  ensure privacy, confidentiality and integrity. The major feature goals of cryptography are:   confidentiality, data integrity, authentication and non-repudiation. These are achieved by using the following cryptography schemes: Encryption, Hash Functions, Message Authentication Codes (MAC) and Digital Signatures. There are three types of Cryptography: Symmetry, Asymmetry and Hybrid [22].

This paper presents a hybrid cryptographic model called ABS comprising Advanced Encryption Standard (AES) Blake2b and Schnorr Signature Scheme which is resource-efficient for better data security in Mobile Cloud Computing (MCC).

• A.    Mobile Cloud Computing

MCC is an integration of Mobile Computing and Cloud Computing. Mobile Cloud Computing integrates the basic functional architectures of mobile communication using either wireless access point or radio tower (Wi-Fi, 3G, 4G or 5G technologies) to access cloud resources (Servers and Virtual Machines) [7] due to resource limitations of the mobile devices as shown in the Fig. 1 below

• B.    MCC Model

MCC model consists of three components mainly as shown in Fig.1. These components include [23]:

• •    Mobile Terminal : This refers to the portable and movable devices such as smart phones, PDA and tablets.

• •    Cloud: It contains servers providing services like Infrastructure-as-a-Service  (IaaS),  Platform-as-a-

• Service (PaaS) and Software-as-a-Service (SaaS).

• •    Mobile Network: It makes services available to mobile devices. So whenever we talk about the security in MCC, we should consider the security and privacy issues in all these three aspects.

Fig.1. Overview of Mobile Cloud Computing [17]

• C.    MCC Issues

In Mobile Cloud Computing, the data storage and processing are done in the cloud [15]. The security and privacy of user’s data that is stored on cloud is one of the major issues needed to be resolved in MCC [12] because MCC users may store all confidential data in the cloud for either a short or long term usage with little or no control over it while a malicious mind in disguise of a cloud staff may access the confidential data, steal and pass it on to user’s competitors [19]. Therefore, the security of the data in the cloud becomes a real issue. Moreover, the user data needs to be protected not only from the outside attackers but also make it inaccessible to the cloud service providers.

• D.    Cryptography