World is moving towards automation in every aspect. Things around us are becoming automated day-by-day with the advent of artificial intelligence. Internet of Things (IoT) has played a major part in growth of technology. Almost all the industries and organizations in the world have adopted the Internet of Things in their daily régime in order to sophisticate their work. This has led to a worldwide revolution in technology. The cloud computing technology has played a vital role in the IoT infrastructure. Every IoT infrastructure makes extensive use of cloud technology as their server for processing and storing data. General IoT architecture is Client-Server architecture, the cloud being rendering the server roles of processing and storing data. There have been new security constraints related to the cloud technology due to which the role of cloud technology is being reconsidered in the IoT infrastructure. With the rise of cryptocurrency gave rise to new technology, the blockchain. Blockchain was invented to serve as the public transaction ledger for cryptocurrency bitcoin. The advent of blockchain has made the need of trusted authority or a centralized server obsolete. This bitcoin technology design has since then inspired other applications. All the major organizations over the world are spending huge for developing the technologies with the help of blockchain.