IOSR Journal of Computer Engineering (IOSR-JCE) e-ISSN: 2278-0661,p-ISSN: 2278-8727, Volume 17, Issue 2, Ver. III (Mar – Apr. 2015), PP 63-66 www.iosrjournals.org DOI: 10.9790/0661-17236366 www.iosrjournals.org 63 | Page Secure Data Storage in Cloud Using Encryption and Steganography Akhil S Killawala 1 , Kaustubh R Kulkarni 2 , Nishant D Gohel 3 , 1,2,3 Dept. of Computer EngineeringK J Somaiya College Of Engineering,Mumbai-77,Maharashtra,India Abstract: In this project, we focus on cloud data storage security, which has always been an important aspect of quality of service. To ensure the correctness of users' data in the cloud, we propose an effective and flexible scheme combining cryptography and steganography. Encryption module encrypts the files before they are uploaded and decryption module decrypts them when they are downloaded. The text steganography inserts a watermark within an html file to uniquely identify it’s owner. The image steganography embeds the watermark within an image file. Index Terms: Secure Storage, Cloud, Encryption, Text Steganography, Image Steganography. I. Introduction Cloud computing has been envisioned as the next generation architecture of IT enterprise. In contrast to traditional solutions, where the IT services are under proper physical, logical and personnel controls, cloud computing moves the application software and databases to the large data centers, where the management of the data and services may not be fully trustworthy. This unique attribute, however, poses many new security challenges. In this project, we focus on cloud data storage security, which has always been an important aspect of quality of service. To ensure the correctness of users' data in the cloud, we propose an effective and flexible scheme combining cryptography and steganography Encryption module encrypts the files before they are uploaded and decryption module decrypts them when they are downloaded. The text steganography inserts a watermark within an html file to uniquel y identify it’s owner . The image steganography embeds the watermark within an image file. The project also has authentication and access control features, for example, blocking a particular suspicious IP address. All malicious attempts to access the system are logged for future reference. Mobile alerts module has also been incorporated on an experimental level to simulate an attacker so that, thus alerted , the owner can take appropriate steps like blocking that IP address etc. II. Existing System From the perspective of data security, which has always been an important aspect of quality of service, Cloud Computing inevitably poses new challenging security threats for number of reasons. Firstly, traditional cryptographic primitives for the purpose of data security protection can not be directly adopted due to the users’ loss control of data under Cloud Computing. Therefore, verification of correct data storage in the cloud must be conducted without explicit knowledge of the whole data. Considering various kinds of data for each user stored in the cloud and the demand of long term continuous assurance of their data safety, the problem of verifying correctness of data storage in the cloud becomes even more challenging. Secondly, Cloud Computing is not just a third party data warehouse. The data stored in the cloud may be frequently updated by the users, including insertion, deletion, modification, appending, reordering, etc. To ensure storage correctness under dynamic data update is hence of paramount importance. These techniques, while can be useful to ensure the storage correctness without having users possessing data, cannot address all the security threats in cloud data storage, since they are all focusing on single server scenario and most of them do not consider dynamic data operations. As an complementary approach, researchers have also proposed distributed protocols for ensuring storage correctness across multiple servers or peers. Again, none of these distributed schemes is aware of dynamic data operations. As a result, their applicability in cloud data storage can be drastically limited. III. Problem Definition Cloud computing moves the application software and databases to the large data centers, where the management of the data and services may not be fully trustworthy. This unique attribute poses many new security challenges which have not been well understood. In this article, we focus on cloud data storage security, which has always been an important aspect of quality of service. We have to ensure the correctness of users' data in the cloud as well.