Cloud computing has increasingly been used to support data-driven services for healthcare, transportation, energy and governance in smart cities. The scale-out, efficiency of cloud computing can provide the user with a power to do real-time analytics, and make smart decision; in-order to achieve this purpose that presents serious challenge when it comes to confidentially, privacy, integrity and data resiliency. In this paper, we survey the recent developments on secure cloud data in smart cities. I also mention a few of those researchers and the papers, such as: smart city security framework, IoT & cloud integration, mobile cloud threats, SCADA next-gen migration and 6G-enabled audit. POST-CATEGORIES: pentest-mgmt. Comparative analysis also finds some remaining research blocks in policy-aware cryptography, verifiability auditing and resilient city-scale infrastructures. The chapter concludes with a summary of future research directions to enhance the security and transparency from the cloud-based smart cities.