INTERNATIONAL JOURNAL OF RESEARCH IN COMPUTER APPLICATIONS AND ROBOTICS www.ijrcar.com Vol.2 Issue.11, Pg.: 150-154 November 2014 S. Prasanna & S. Ramya Page 150 INTERNATIONAL JOURNAL OF RESEARCH IN COMPUTER APPLICATIONS AND ROBOTICS ISSN 2320-7345 IMPLEMENTATION OF KEY AGGREGATE CRYPTO WITH STEGNOGRAPHY FOR SECURED DATA SHARING IN CLOUD COMPUTING S. Prasanna 1 , S. Ramya 2 1 Department of Computer Science & Engineering, Mailam Engineering College, Mailam, Tamil Nadu, India 2 Computer Science and Engineering at Mailam Engineering College, Mailam, Tamil Nadu, India. Abstract Data sharing is main functionality about in cloud computing. In the existing system, Although Cloud Computing is vast developing technology, the challenging problem is how to effectively share encrypted data in cloud computing. In the proposed system, data owner randomly generates public/master-secret key pair after account is created in the server. Data owner encrypts the data, public key and data index & then uploaded in the Cloud Server. Data owner Generates Aggregate Decryption Key (ADK) using its master-secret key, Data owner can share the data to other Users by sending its ADK to those via Secured E mail. Original Data, Index and the Public key is downloaded only after Verification of ADK. In the modification process, we are using steganography. Encrypted Outlet of original Data, Public Key and Index is made stegno into an Image. Data owner has to share the selected Image along with the ADK to download the Original Data. Remote Cloud would authenticate the Image along with the ADK to download Data which ensures security. Keywords: Cloud computing, Aggregate decryption key, Advanced encryption standard, Public/private key. 1. Introduction CLOUD storage is gaining popularity recently. In enterprise settings, we see the rise in demand for data outsourcing, which assists in the strategic management of corporate data. It is also used as a core technology behind many online services for personal applications. Nowadays, it is easy to apply for free accounts for email, photo album, and file sharing and/or remote access, with storage size more than 25 GB (or a few dollars for more than 1 TB). Together with the current wireless technology, users can access almost all of their files and emails by a mobile phone in any corner of the world. Considering data privacy, a traditional way to ensure it is to rely on the server to enforce the access control after authentication, which means any unexpected privilege escalation will expose all data. In a shared-tenancy cloud computing environment, things become even worse. Data from different clients can be hosted on separate virtual machines (VMs) but reside on a single physical machine [1] [2] [3].