Cloud storage is one of the cloud computing services which allows data users to store their data remotely to the cloud. Thus, most individuals, institutions, and organizations are outsourcing their data to the cloud. Most popular cloud-based storage services are Amazon S3, Google Drive, Microsoft Azure, Apple iCloud, Dropbox, etc. Cloud storage service brings significant benefits to data owners, say, (1) reducing capital and management costs (2) reducing cloud users’ burden of storage management and equipment maintenance, (3) avoiding investing a large amount of hardware, (4) accessing data over the Internet from any location from any devices such as desktop computers, laptops, tablets, and smartphones which offers increased flexibility and accessibility.