The Internet-of-Things (IoT) paradigm is an emerging twenty-first century technological revolution, a concept that facilitates to communicate with objects, devices, and machines at unprecedented scale. Nowadays, IoT is extensively applied to numerous applications such as intelligent transportation, smart security, smart grid, and smart home. Now, considering that in the near future, millions of devices will be interconnected and will be producing enormous data, the privacy and security of data going to be challenged and private information may leak at any time. This chapter presents an overview of the IoT and security concerns on big data while we discuss privacy and security approaches for big data with reference to infrastructure, application, and data.