الفهرس 
CLOUD COMPUTING OVERVIEW
CryptographyOnly 14 pages are availabe for public view
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Abstract
Cloud is considered as a huge pool of resources and services from where the service or resource can be used whenever needed by paying the amount for the service being used. The basic goal of cloud architecture is to provide secure, appropriate, on-demand access to configurable computing resources pool over internet. The cloud computing idea relies on a most essential rule of “reusability of IT capabilities”. Cloud computing provides four fundamental deployment models. These models are the public, private, hybrid, and community cloud. Besides the providing benefits of cloud computing, also still there are some obstructions which should to be eliminated. These obstructions considered as challenges which can involve data protection, performance, control and reliability.
Organizations are worried about attacks, while transmitting their data to the cloud environment. Data considered a very important concern for any enterprise. Enterprises seek to secure their sensitive data confidentiality for intruders. There are several methods for protecting data security such as third party auditing and encryption algorithms.
Cryptographic provides a secure communication channel between data sender and the receiver by protecting either data or encryption key or both from adversaries. But, the objective of steganography is making the communication between different parties unnoticeable. The strength of cloud security system can be enhanced by merging cryptography and steganography techniques together.
In this work, we present a security model to cloud data protection by providing a higher level of security using both of cryptography and steganography algorithms. Our model includes three phases for hiding data. First, Hashing phase that gets the secret data file and computes its hash code using SHA-256 and produce 256 bit or 32 byte hash code. Then, Encryption phase encrypts the file data using AES-256 and encrypts both of hash code and the new session key using RSA. Then combine the output of AES-256 and RSA in one stream and send it to the embedding phase. Finally, in Embedding phase, we embed the output of encryption phase into an image using the advanced LSB algorithm. Process of development and implementation of this work is proven and documented.
We validate the effectiveness of our design by carrying out a detailed security analysis. This analysis shall prove the correctness of our design in terms of data confidentiality in each stage of user interaction with the cloud