Nowadays, cloud computing is most popular and modern technology of storing the large amount of information on the internet and accessing it from anywhere. Costs reduction, universal access, availability of number of applications and flexibility is a number of reasons for popularity of cloud computing. Users store sensitive information on cloud, providing security becomes important aspect as these cloud service providers cannot be trusted one. As the cloud computing assures user to provide the data, the cloud computing environment failure may result in loss or unavailability of data so the concept of Multi-Clouds is introduces. Dealing with single cloud” service providers are anticipated to become infamous with customers due to scare of service availability failure and the possibility of malicious intruders in the individual cloud. Multi-clouds guarantee to provide service at any cost if there is any failure at any cloud due to any reason. The use of multi-clouds as it can tackle the security and mainly availability issues much effectively than single cloud that affects cloud computing user. The proposed work surveys recent research related to single and multi cloud security and addresses possible solutions. This work aims to promote the use of multi clouds to solve problem of data availability due to failure in individual cloud. To provide data confidentiality as well as data integrity, security mechanism which uses an image audio secret sharing scheme(ASS) cryptography instead of visual secret sharing scheme(VSS)
