13-06-2013, 04:54 PM
AN APPROACH FOR DATA STORAGE SECURITY IN CLOUD COMPUTING
AN APPROACH.docx (Size: 669.35 KB / Downloads: 42)
INTRODUCTION
Cloud computing is the most demanding and emerging technology throughout the world. Cloud computing is an Internet based computer technology. Some of the major firms like Amazon, Microsoft and Google have implemented the “CLOUD” and have been using it to speed up their business. Cloud computing has given a new dimension to the complete outsourcing arena (SaaS, PaaS and IaaS) and they provide ever cheaper powerful processor with these computing architecture.
The major thing that a computer does is to store in the available space and retrieve information whenever requested by the authenticated user. The pioneer of Cloud Computing vendor,(example) Amazon S3 is storage for the Internet. Amazon S3 provides a simple web services interface that can be used to store and retrieve any amount of data, at any time, from anywhere on the web. It also allows developer to access the highly scalable, reliable, secure, fast, inexpensive infrastructure that Amazon uses to run its own global network of web sites. From the viewpoint of data security, which has always been an important aspect of quality of service, Cloud Computing unavoidably poses new challenging security threats for number of reasons.
RELATED WORK
The Internet began to grow quickly in the 1990s and the increasingly sophisticated network infrastructure and increased bandwidth developed in recent years has dramatically enhanced the stability of various application services available to users through the internet, thus marking the beginning of cloud computing networks services. Many organizations tried to enhance for their security constraints, for their secure database, for their web application but they have not achieved a high-level security for their organization .Data integrity quality of correctness, completeness, wholeness, soundless and compliance with intention of the creator of the data. It is achieved by preventing accidental or deliberate but unauthorized insertion, modification, or destruction of data in database. Ensuring the integrity of data really means that it changes only in response to unauthorized transactions (see Fig.1) given stats confirm that the “security” is the main challenge in cloud computing for example IDC recently conducted a survey of 244 IT executives/CTOs and their line-of-business (LOB) colleagues to gauge their opinions and understand their companies’ use of IT cloud services. Security ranked first as the greatest challenge or issue of cloud computing.
PROBLEM STATEMENT
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:
1. Data stored on cloud servers is not completely secure from infection. While popular cloud services such as Google Docs are equipped ith virus scanning software, there is still the possibility of an internal or external attack affecting your data.
2. The data stored in the cloud may be frequently updated by the users, including insertion, deletion, modification, appending, recording, etc. To ensure storage correctness under dynamic data update, distributed protocol is used.
Data storage in cloud is a process where the owner stores his data, files and application through a cloud storage provider (CSP) in cloud servers. At the time of file storage, security key is used to secure the file from unauthorized access and then safely stored in the cloud Users who likes to access the file from cloud needs the security key to retrieve the file. User sends a key request to the owner and retrieves the file from the cloud after security key sent by the owner. File can’t accessed by any unauthorized person or person who entering unmatching security key .For additional security, blocking IP address of the system those who illegally trying to access the file.
SECURE DATA STORAGE IN CLOUD
In cloud storage system, companies stores their data in the remotely located data server. Accordingly, correctness of the data is assured. Even though sometimes unauthorized person may modify or delete the data which leads to server compromise and/or random Byzantine failures. Because it can be the first step for fast recovery of the storage errors. The cloud storage systems propose an effective and flexible distributed scheme with explicit dynamic data support for file distribution across cloud servers. By computing homomorphic token using universal hash function which can be perfectly integrated with the verification of erasure-coded data.As well as it identifies misbehaving servers. Finally, the procedure for file retrieval and error recovery based on erasure correcting code is outlined.
Token correctness:
It achieves assurance for data storage correctness and data error localization, using pre-computed token. Before sharing file distribution using pre-computes a certain number of shortest verification token are generated that will ensure security for a block of data in a file in cloud storage. When the user wants to make sure the storage correctness for the data in the cloud, he challenges the cloud servers with a set of randomly generated block indices. After getting assurance of the user it again asks for authentication by which the user is confirmed to be the Authenticated user. Upon receiving assurance, each cloud server computes a short “signature” over the specified blocks and returns them to the user. The values of these signatures should match the corresponding tokens pre-computed by the user. Suppose the user wants to challenge the cloud server’s t times to make sure the correctness of data storage. Then, he must pre-compute t verification tokens for each function, a challenge key and a master key are used. To generate the ith token for server j, the user acts as follows the details of token Generations are shown in Algorithm 1.
Cloud Data Storage Module
Cloud data storage, a user stores his data through a CSP into a set of cloud servers, which are running in a simultaneous, the user interacts with the cloud servers via CSP to access or retrieve his data. In some cases, the user may need to perform block level operations on his data. Users should be equipped with security means so that they can make continuous correctness assurance of their stored data even without the existence of local copies. In case that users do not necessarily have the time, feasibility or resources to monitor their data, they can delegate the tasks to an optional trusted TPA of their respective choices. In our model, we assume that the point-to point communication channels between each cloud server and the user is authenticated and reliable, which can be achieved in practice with little overhead. Using screen shown in Fig.3.
CONCLUSION
This paper briefly explained the problems of data security in cloud data storage. And also provided a way out to ensure user correctness. We propose a distributed scheme through homomorphism token with distributed verification of erasure-coded data. Additionally, the technique provides a process to avoid colluding attacks of server modification by unauthorized users. We believe that data storage security in Cloud Computing, an area of challenges and of dominant significance, is still in its infancy to be identified. We envision several possible directions for future research on this area. It allows Third Parity Auditor to audit the cloud data storage without demanding users’ time, probability.