Cloud computing opens a new horizon of computing for business and IT organizations. Since 2007, we have seen an explosion of applications of cloud-computing technology, both for enterprises and individuals seeking additional computing power and more storage at a low cost. Small-and medium-scale industries find cloud computing highly cost effective as cloud infrastructures replace the need for costly physical and administrative infrastructures, and offer a flexible, pay-as-you-go payment structure. Opportunities provided by the cloud have led to estimates that the growth of global cloud computing market could be 30% compound annual growth rate (CAGR), reaching $270 billion in 2020 (http://www.marketresearchmedia. com/?p=839, accessed December 7, 2015).Although cloud computing offers numerous facilities and contributes extensively to the advancement of information technology, cloud security is not transparent. Clouds use the multitenant usage model and virtual ization to ensure better utilization of resources. However, these fundamental characteristics of cloud computing are a double-edged sword − the same properties also make it difficult to prevent and investigate cloud-based crimes and attacks on clouds and their users. Besides attacking cloud infrastructures, adversaries can use clouds to launch attacks on other systems. For example, an adversary can rent hundreds of virtual machines (VMs) to launch a distributed denial of service (DDoS) attack. After a successful attack, the adversary can erase evidence that is important to trace the attack by turning off the VMs. Criminals can also keep their secret files (e.g., child pornography, terrorist documents) in cloud storage and remove the files from local storage to remain clean. To investigate such crimes involving clouds, investigators have to carry out a digital forensic investigation in the cloud environment. This particular branch of forensic has become known as cloud forensics.While computer forensics itself is not well matured yet, cloud forensics imposes greater challenges on digital forensics. As many of the assumptions of traditional digital forensics are not valid in the cloud computing model, the traditional digital forensics tools and procedures are not suitable for investigating crimes involving clouds.