© 2013. Amanpreet Kaur, Gaurav Raj & Dheerendra Singh. This is a research/review paper, distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License http://creativecommons.org/licenses/by-nc/3.0/), permitting all non- commercial use, distribution, and reproduction inany medium, provided the original work is properly cited. Global Journal of Computer Science and Technology Cloud and Distributed Volume 13 Issue 3 Version 1.0 Year 2013 Type: Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 0975-4172 & Print ISSN: 0975-4350 Multi Round Selective Encryption using AES Over Storage Cloud By Amanpreet Kaur, Gaurav Raj & Dheerendra Singh Lovely Professional University, India Abstract - Cloud computing is the re-incarnation of the client-server architecture. It is highly promising technology because of its unlimited resource provisioning and data storage services which help us in managing the data as per requirements. Due to the use of internet and vital remote servers to maintain the data and applications, the cloud computing environment becomes open for the attackers to attack on the user data and communication services. This paper mainly focuses on the user authentication and data security over the Broker Cloud Computing Paradigm by purposing new cryptographic technique named as Multi Round Selective Encryption using AES. Along with this, we compared our approach with existing cryptographic techniques as AES, Blowfish and Selective encryption to find out its pros and cons. The Multi Round Selective Encryption with AES is the best suitable technique where the file size is large because it gives fast execution by maintaining the encryption complexity as compared to selective encryption technique in public and hybrid cloud. Keywords : AES, blowfish, selective encryption, storage cloud. GJCST-B Classification : E.3 MultiRoundSelectiveEncryptionusingAESOverStorageCloud Strictly as per the compliance and regulations of: