International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-2, July 2019 4152 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: B3171078219/19©BEIESP DOI: 10.35940/ijrte.B3171.078219 Abstract: Many companies which essentially required cloud computing services are still in ambivalence whether to adopt it or not. In this research paper an attention has been drawn on security of storage as a Service which is an integral part of Infrastructure as a Service which provide famous CSP, AWS. Whenever someone rent the storage from the cloud service provider, chances of its compromising can take place. Therefore it is intelligence to encrypt the data before uploading it to the cloud and more intelligently divide the data into fragments and encrypt these fragments separately and then upload on cloud. Suppose that if this data is divided into n fragments then n algorithm are required to encrypt these fragments or use single one algorithm and change its key n times otherwise if only one key will be used and someone steal this key then all fragments will be decrypted with the same key. Many algorithms like DES, AES, RSA, Elgamal and Blow Fish are there but they all are static in nature and one more weakness of these algorithms is that size of encrypted file increased. While some researchers used these algorithms in combination and some used double encryption, nevertheless nature remains static and decrypted file size increase rapidly. Now, there is a requirement to design a data sensitive algorithm which could sense data and produce different key for different data automatically. In this paper Two Pass Multidimensional Key Generation and Encryption Algorithm has been proposed which will sort the above problem. Another beauty of this algorithm is that it checks the integrity of the documents while decrypting. Out of millions or billions of characters if only one character or word is altered or removed then this algorithm will show that documents integrity has been violated. Index Terms: Cloud Computing; Two Pass Algorithm; Data Sensitive; Storage Security; User Independent. I. INTRODUCTION Cloud Computing is a technology for performing computation through Internet on remote location. Cloud computing was first coined by Prof. John McCarthy in 1960. Initially cloud computing was growing rapidly and its field was spreading fast. Large scale companies were adopting the cloud computing happily. As soon as the news of data leakage and hacking from cloud came, it leveraged a bad impact in users’ mind. Cloud Computing is a very popular and versatile environment to support commercial business industries. It is rich with a no. of definitions. According to Prof. John McCarthy “If computers of the kind I have advocated become the computers of the future, computing may someday be organized as a public utility just as the telephone system is a public utility. The computer utility could become the basis of a new and important industry”[7]. Revised Manuscript Received on July 15, 2019. Mohd. Tajammul, Department of Computer Science, Jamia Millia Islamia, New Delhi, India. Rafat Parveen, Department of Computer Science, Jamia Millia Islamia, New Delhi, India. The National Institute of Standards and Technology (NIST) define cloud computing as “A model for enabling convenient, on demand network access to a shared pool of congurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction. This cloud model promotes availability and is composed of five essential characteristics, three service models, and four deployment models” [18, 21]. A. Deployment models of cloud computing • Public cloud-: This is one of the types of cloud deployment model in which everybody is allowed to avail services. It is highly suggested to go for this cloud model if data or computation is not highly sensitive or secure [7]. • Private cloud-: This is one of the types of cloud deployment model in which everybody is not allowed to avail services. It is highly suggested to go for this cloud model if data or computation is highly sensitive or secure. It is available for any particular company, organization or an individual [19, 23]. • Community cloud-: This is one of the types of cloud deployment model in which every body from a community or from a particular group only is allowed to avail services. It is highly suggested to go for this cloud model if data or computation is of middle level sensitive or secure [19, 22]. • Hybrid cloud-: This is one of the types of cloud deployment model in which everybody is allowed to avail services. It is combination of any of the above two cloud models [7, 22, 23]. B. Service Models of cloud computing • Software as a Service (SaaS)-: Under this service, software is provided to the client on which he or she can perform operations for instance Gmail. Some well known SaaS providers are SalesForce.com, Microsoft, IBM and Oracle, NetSuite [18]. • Platform as a Service (PaaS)-: Under this service, a platform is given to the client, on which client can develop his or her applications. Some well known PaaS providers are Microsoft Azure, GAE [18]. • Infrastructure as a Service (IaaS)-: An infrastructure like CPU or storage is given to the client, on which he or she can perform computation or upload data for future use. Popular IaaS providers are Amazon Web Services Joyent, Flexiscale, GoGrid [18]. Mohd. Tajammul, Rafat Parveen Two Pass Multidimensional Key Generation and Encryption Algorithm for Data Storage Security in Cloud Computing