1.     Introduction

There are bundles of reasons that cloud storage is beneficial for an organization. The main reason is low cost as the company or organization get huge amount of data capacity without investing in hardware for creating own data center. Only a swipe of credit card can manage huge data capacity for the organization without any worries about maintenance or backup of data. This increasing trend of using cloud storage by the companies is alarming as well. The organizations are holding data on virtual servers that can be accessed by millions of users at a time. If proper security system is not developed for the preservation of data, then the organization may face huge downfall. High level security system should be developed for data placed on cloud storage to keep data safe from unauthorized persons who can use your data for other purposes.

2.     Cloud Storage

Cloud storage is a way of storing structured or unstructured data for anytime availability from anywhere with secure authentication. In other words it can be said that cloud storage is a model of networked online storage system, where data can be stored. Cloud storage is becoming popular because of its online accessibility and reducing cost for an organization that wants to hold large amount of data. As Gercke emphases on the usage of cloud storage by saying that we are moving to cloud network every day without knowing (2011). Companies over the internet prefer to use cloud storage for holding huge amount of data about their customers and their transactions. It is like virtually accessing the server to get specific data. Looking at the architecture of cloud storage it is revealed that it follows the structure of cloud computing using the hardware placed in data center by the cloud storage service provider. Cloud storage is a benefit to the companies accompanied by security risks as well.

For the easy and fast access of data it is preferred to use cloud storage services to provide swift access to the customers. However this is not being shown to the customer, but an API is used to allow the customer access data from cloud storage.  There are risks attached to cloud storage but this reduces set up cost for the companies. When starting a new business; company need to have a storage system for its record that will need to have a large storage system and invest huge money for this purpose. Cloud storage is the best solution for this problem. The cloud storage providers let the companies save their money and store data using cloud storage services.

3.     Benefits of Cloud Storage

There are number of benefits that attract the companies use cloud storage.

Kusnetzky believes that the main advantage that cloud storage offers is the reduction of cost for the organization (2010). For setting up a new datacenter within the organization will cost a lot and its maintenance and backup will needed to be taken care every week or month. For this purpose the company will need to have more employees who will be dedicated to data center only. On the other hand the Cloud storage providers let the organizations do these tasks for them. The cloud storage service uses its hardware for the storage of organization’s data.

The other benefit of using cloud storage is that the cloud storage service providers maintain all the hardware so that the organizations can access their data without any interruption.

Cloud storage also offers the feature of back up all the data if there is something wrong with the server. This makes the data of the organization safe.

Cloud storage also offers different features like copy, synchronization, sharing and easy access of data from anywhere and any digital device (WU et al. 2012).

Cloud Storage Service

There are different cloud storage services available over the internet that provide very easy and convenient way for the user to save his important data on cloud server so that they can access it from anywhere they want. The most famous cloud storage services available are DropBox, Mozy, CrashPlan, CloudMe, Ubuntu One, Wuala and TeamDrive (Fraunhofer Verlag, 2012).  Other famous giant companies of technology are also doing their part in the development of cloud storage services like Microsoft and Apple. Apple introduced its iCloud and SkyDrive by Microsoft. In the near future these services will be used more for storing data on virtual drive. Most of these companies store their data in their data centers in US. Some of these cloud storage services also provide full backup services for your precious data.

Here is short description of famous cloud storage services and their security models they are using for the security of data.

 i.      Dropbox

Dropbox is one of the famous and well known cloud storage service available till available on internet. It is available for famous operating systems like Windows, Mac OS and Linux. It is also available for Smartphone like iPhone, Android and Blackberry devices. This service is secured for storing data like it requires username and password to access you’re account and further more there is facility of encryption of data. Dropbox encrypts data during the transmission of data and also encrypts data on server side. However, it does not encrypt data on user devices because it uses its own encryption key. However the data is secure on Dropbox server by encryption. There is no backup facility.

ii.      Mozy

Mozy is another cloud storage service being run on Windows and Mac OS with web user interface and also available for Android and iPhone. This cloud storage service is also secure while we look at the authentication process to access your account. Mozy also encrypts data but its methodology is bit different from Dropbox. Mozy encrypts data during the transmission, but it does not encrypt data on server while it encrypts data on client’s side before transmission.

 iii.            Cloud Me

Cloud me is a cloud storage service that can be enjoyed fully using newer versions of Windows or Internet Explorer. Verlag states that this service can be used on other web browsers as well but with limited features (2012). This service has a very simple UI and easy to upload service. While talking about the main issue about security of data on server, then it is notable that Cloud Me does not encrypt data even on the server. Even the data is not encrypted during the transmission of data between user and administrator. This lack in security makes the data unsecure. The sharing feature of CloudMe is also not as convincing as it provides a URL that is different for subscribers, non-subscribers. The main disadvantage in this URL is that it contains the username of the provider of the file that makes it a bit unsecure from the safety point of view of data.

4.     Security risks to Data on Storage cloud

As the cloud storage is an open way for the hackers to access data of the organization then it must be assured that the data on cloud storage provider is protected in different ways. For the security of data on cloud storage there are main concerns that should be taken into notice by the organization.

The threats attached to cloud storage increases as the accessibility to data stored is increased. In cloud computing the data is stored on more than one location, so there are more chances of physical access to data center. The data is being accessed through cloud storage frequently and this leaves a space for unauthorized persons to access data. The data is being replicated during the accessing of data. This can allow anyone to access through information of organization.  However the data can be replicated on server through different methods that depend on the selection of service by the user. There is a way decrease risks of theft of information through encryption of data on the server. Once the data is encrypted on the server it cannot be decrypted without completing authentication process.

The other risk to data security on cloud storage is that, the company offering cloud storage service is a large organization providing cloud storage services to other companies as well. This means that the number of employees will be big as well who will have access to data of different organizations as well. It means that any of the employees can also access the data and information through authentication names and passwords. The best solution to mitigate this security risk is by limiting employee’s access to server. This will help in securing data on cloud storage.

In cloud storage, there are number of networks combined to create a major network to make it accessible by millions of visitors. When a cloud storage company offers it services then it does not holds data at one place but connects different networks like Local area network and storage area network using wide area network (WAN).

As there are huge numbers of people accessing cloud storage, then by mistake or with the intention of hacking the data on cloud storage become a bit unsecure. However, the best solution to save data on cloud storage is by using is encryption.

5.     Ensure Data Security on Cloud Storage

The basic security models should be working on data center providing services of cloud storage.

 i.      Physical Security

The data center should be totally secure that no unauthorized person is not allowed to enter. The data center should have employees 24/7 for customer assistance. The other important thing about data center is that it should be auditable, meaning that there must be records of everything like audio visual aids. The record of the data center should be clean.

ii.      Storage Architecture Security

The method for the authentication should be secure so that no one can easily breach into the system and extract data of the organization (McClure et al 2009). This means that the management should make such authentications that are hard to hack. If there is any alarming activity on the server side of cloud storage then you should have access to the service provider, so that you can alert them about attack or safety of data. The server side should not activate any service unless the authentication process is not verified through different authentication processes.

 iii.            Network Security

It is important that if there is a fiber channel in network then it must support security feature for configuration and changes being implemented by the administrator. Even the username and passwords for authentication should be auditable.

  iv.            Storage access and Management Security

The management software should always username and passwords in encrypted files so that they are not shown to the hacker. The cloud storage should have a session timeout as well so that no unauthorized person is able to access the server.

6.     Conclusion

Cloud storage is meant for storing your data on a server easily accessible from internet anywhere. There are advantages and disadvantages of cloud storage services. As the usage of cloud storage is increasing by organizations so there is a need to make this system as secure as possible. The information or data of an organization is considered to be an asset so it must be preserved from destruction or stealing. There are many cloud storage service providers who are working on making their security system better. Security is the main issue for the data on local server or cloud server. If the cloud storage server is not secured then the organizations may face a huge lose who are using cloud storage services for holding their huge amount of data.

7.     References
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  2. Verlag, H. (2012) On THE Security of Cloud Storage Services. Germany: Fraunhofer Institute for Secure Information Technology SIT.
  1. McClure, T., Oltsik, J. (2009). Evaluating Cloud Storage Security. Enterprise Strategy Group.
  1. Wang, Q., Wang, C., Li, J., Ren, K. and Lou, W. (2009). Enabling Public Verifiability and Data Dynamics for Storage Security in Cloud Computing. Chicago: Illinois Institute of Technology.
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  1. Wang, C. (2009) Ensuring data storage security in Cloud Computing. Retrieved August 28, 2012 from http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5201385&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5201385
  1. Zhou, M. (2010) Security and Privacy in Cloud Computing: A Survey. Retrieved August 28, 2012 from http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5663489&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5663489
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