Cloud is a successful paradigm for on-demand services over the Internet with the help of a large amount of virtual storage. Amazon, Google, Cisco, IBM, Microsoft are the major Cloud providers in the current market segment. One of the main features of cloud computing is that it provides extensive computing infrastructure to the user and the cost of its services is also less. There are various types and models in cloud computing like public cloud, private cloud, hybrid cloud, and community cloud. According to Cloud Security Alliance (CSA), more than 70 percent of the global businesses are nowadays operating on the cloud. The growing popularity of cloud computing is also causing cyber-attacks and rising concerns for cloud security. Data protection is also one of the primary security concerns for many organizations. Cloud security refers to various techniques, policies and technologies that protect cloud data, applications, and infrastructure. The leading popular security techniques include SSL (Secure Socket Layer) Encryption, Intrusion Detection System, Multi contract-based Access Control, etc. Securing the systems involves the efforts of cloud providers as well as the clients that use them, whether an individual, small to medium business, or enterprise uses. Although a lot of techniques are recommended for data protection in cloud computing, but still there are plenty of challenges to overcome. The primary objective of this chapter is to provide an up-to-date understanding of cloud security concerns and mitigation techniques so that the users can make educated decisions regarding cloud adoption strategies.