In recent years, smart mobile devices, such as smartphones and tablets, have increasingly become the computing platform of choice. Smart mobile devices now can not only perform intensive computation, but also sense, recognize, and share users’ contextual data with others. However, they are still resource-constrained in many ways, e.g., battery, storage, network, programmability, etc. To significantly expand their capability, cloud technology, driven by leading IT companies equipped with millions of compute-cores and unlimited storage space, has certainly presented a great opportunity to augment the capabilities of mobile devices.To advance the state-of-the-art, my research focuses on cloud-enabled mobile systems for sensor data processing and sharing. I enable compute- and data-intensive workloads on mobile devices and large-scale secure sharing of sensor data by adaptively using cloud infrastructure and/or by using mathematical analysis. In this talk, I will first introduce an emerging class of mobile sensing applications and how we enable such applications on mobile devices. Also, I will discuss how we can preserve users' privacy when we use cloud-based photo sharing services, while still allowing the service providers to perform useful processing for mobile devices.