Ali Asghar Mohammadi - Software Engineering Department, Zanjan Branch- Islamic Azad University
Javad Mohammadi - Payam Noor University of MahmoudAbad, Mazandaran, Iran
Mehdi Bakhoda - Mahmoodabad, iran

Cloud Computing is a set of IT services that are provided to a customer over a network on a leased basis and with the ability to scale up or down their service requirements. Usually cloud computing services are delivered by a third party provider who owns the infrastructure. Cloud computing is Internet-based computing, whereby shared resources, software and information, are provided to computers and devices on-demand. It is the product of the fusion of traditional computing technology and network technology like grid computing, distributed computing parallel computing and so on. Using cloud computing to run applications requiring heavy and all the calculations are not an advanced system for the Internet provider's servers. On this basis, data processing, software or services online and through a strong connection to the central servers and operational resources needed in the computer is also provided by hundreds super server. Security is one of the major issues of cloud computing, which is connected to the Internet as a result of the negative charge resulting from the performance of applications and traditional security and costs of applying them to slow down and any systems and equipment will not impose computer. In this paper, the authors discuss security issues for cloud computing.

Cloud Computing, Issue, Security, Challenge, Modeling