Cloud computing is the one which offers infrastructure to the client on a pay as you use model by leveraging on the Internet technology. As this model depicts the electricity billing it is often termed as utility computing. It offers various services to the client based on the need. The need of the resources can be scaled up or down on the basis of the requirement. The IT sectors started using cloud service models. As the use of cloud increases day by day the concerns of cloud also gets increased. There are number of data breaches that are happening day by day that affect the cloud growth. The major concern in adapting cloud is its security. The companies have lot of data that gets increased each day enlarges the complication of data privacy and security. The data that we talk can be classified as either stagnant data i. e. , for simple storage as offered by Amazon's Simple Storage Service (S3) or it can be vibrant that changes often. The solution available to protect the stagnant data will be to simply encrypt the data before it gets stored in the server. In order to solve the issues of vibrant data the techniques are being proposed to work out on the encrypted. This paper is a survey of different security issues that affects the cloud environment and related work that are carried out in the area of integrity.

1. G. Ateniese, R. Burns, R. Curtmola, J. Herring, Kissner, Z. Peterson,and D. Song, "Provable data possession at untrusted stores,"in Proc. of CCS'07. New York, NY, USA: ACM, 2007, pp. 598–609.
2. A. Juels and B. S. Kaliski, Jr. , "Pors: proofs of retrievability for large files," in Proc. of CCS'07. New York, NY, USA: ACM, 2007,pp. 584–597
3. Q. Wang, C. Wang, J. Li, K. Ren, and W. Lou, "Enabling public verifiability and data dynamics for storage security in cloud computing," in Proc. of ESORICS'09. Saint Malo, France: Springer-Verlag, 2009, pp. 355–370
4. Q. Wang, C. Wang, J. Li, K. Ren, and W. Lou, "Enabling public Auditability and data dynamics for storage security in cloud computing," in Proc. Of ESORICS'09.
5. C. Erway, A. Kupcu, C. Papamanthou, and R. Tamassia, "Dynamic provable data possession," in Proc. of CCS'09. Chicago, IL, USA:ACM, 2009.
6. C. Wang, Q. Wang, K. Ren, and W. Lou, "Ensuring data storage security in cloud computing," in Proc. of IWQoS'09, Charleston, South Carolina, USA, 2009.
7. R. Curtmola, O. Khan, R. Burns, and G. Ateniese, "MR-PDP:Multiple-Replica Provable Data Possession," in ICDCS '08: Proceedings of the 2008 The 28th International Conference on Distributed Computing Systems,(Washington, DC, USA), pp. 411–420, IEEE Computer Society, 2008.
8. H. Shacham and B. Waters, "Compact proofs of retrievability," in ASIACRYPT '08: Proceedings of the 14th International Conference on the Theory and Application of Cryptology and Information Security, (Berlin, Heidelberg), pp. 90–107, Springer-Verlag, 2008.
9. M. A. Shah, M. Baker, J. C. Mogul, and R. Swaminathan, "Auditing to keep online storage services honest," in Proc. of HotOS XI. ,Usenix, 2007.

Cloud Computing Cloud Security Integrity