Towards Secure and Dependable StorageServices in Cloud Computing

Introduction

Cloud storage enables users to remotely store their data and enjoy the on-demand high quality cloud applications without the burden of local hardware and software management.

It provides pay per use service .

Cloud Services Saas : Software as a service model you with access to application softwares .

No installation, setup required for running the application. Service provider will provide us. We just have to pay and use it. 

Examples : Google Apps, Microsoft Office 365. etc…

Paas : Platform as a service provides computing platforms which includes operating system, programming language execution environment, database, web server etc.

Examples : AWS Elastic Beanstalk, Force.com, Google App Engine etc…

Iaas : Infrastructure as a service, provides you the computing infrastructure,  and other resources like virtual-machine disk image library, block and file-based storage, firewalls, load balancers, IP addresses, virtual local area networks(LAN) etc.

Examples : Amazon EC2, Windows Azure, Rackspace etc…

Existing systems 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.

Disadvantage: In the existing system there is no privacy to

the user’s data.Security risks towards the correctness of the

data in cloud.

Proposed systems

In the proposed systems we provide the security to ensure the correctness of users data in the cloud, we propose an effective and flexible distributed scheme with two salient features.

featuresIn this system, we propose an effective and

flexible distributed scheme with explicit dynamic data support to ensure the correctness of users’ data in the cloud.

 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, etc.. on their specific data blocks.

System Requirement Specification(SRS)

Functional Requirements.

Non-functional Requirements.

Software Requirements.

Hardware Requirements.

Functional RequirementsFunctional Requirements refer to very important

system requirements in a software engineering process such as technical specifications, system design ,data manipulation, data processing and calculation modules etc.

Requirement is based on parameters of system performance, software quality attributes, reliability and security, cost, constraints in design/implementation etc.

Non-functional requirements All the other requirements which do not form a part of the above specification are

categorized as Non-Functional Requirements.

Sufficient network bandwidth may also be a non-functional requirement of a system.

Examples: Security Accessibility Availability Backup Disaster Recovery Efficiency Open Source Operability Performance Platform compatibility Recoverability etc…..

Software Requirements

 Operating system : Windows XP.Coding Language : ASP.Net with C#Data Base : SQL Server 2005

Hardware Requirements System : Pentium IV 2.4 GHz.Hard Disk : 40 GB.Floppy Drive : 1.44 Mb.Monitor : 15 VGA Colour.Mouse : Logitech.Ram : 512 Mb.

Block/Architectural diagram

Module DesignSystem moduleFile retrieval & Error RecoveryThird party AuditingCloud Operations.

System moduleUser: users, who have data to be stored in the cloud and

rely on the cloud for data computation, consist of both individual consumers and organizations.

Cloud Service Provider (CSP): CSP provides building and managing distributed cloud storage servers, owns and operates live Cloud Computing systems.

Examples: Microsoft , IBM , Google etc….

Third Party Auditor (TPA): an optional TPA, who has expertise and capabilities that users may not have, is trusted to assess and expose risk of cloud storage services on behalf of the users upon request.

File retrieval & Error recovery

The user can reconstruct the original file by downloading the data vectors from the first ‘m’ servers, assuming that they return the correct response values.

We can guarantee the successful file retrieval with high probability.

Third party Auditing(TPA)In case the user does not have the time,

feasibility or resources to perform the storage correctness verification, he can optionally delegate this task to an independent third party auditor, making the cloud storage publicly verifiable.

TPA should not learn user’s data content through the delegated data auditing.

Cloud Operations

Update operation :In cloud data storage, the user can modify

some data block(s) stored in the cloud, we refer this operation as data update.

In other words, for all the unused tokens, the user needs to exclude every occurrence of the old data block and replace it with the new one.

Cloud operationsDelete Operation : After data being stored in the cloud, certain

data block(s) may need to be deleted. The delete operation we are considering is a general one, in which user replaces the data block with zero or some special reserved data symbol.

Cloud operationsAppend Operation : In some cases, the user may want to increase

the size of his stored data by adding blocks at the end of the data file, which we refer as data append.

In cloud data storage is bulk append, in which the user needs to upload a large number of blocks (not a single block) at one time.

 

ConclusionBy using cloud computing technology the

users can access the data as well as the users can store the huge data to their data blocks instead of storing to their local hardware system.

In the cloud,the data is secure ,the unauthorized users cannot access to the data stored in it..