The Internet of Things (IoT) is an important part of the digital shift because it links billions of things so that data can be sent and collected. The layer of perception, which is Because Internet of Things sensors and gadgets are all connected to each other, they collect private information, which raises security, privacy, and access control issues. People are thinking about using blockchain to make Internet of Things (IoT) gadgets safer and more reliable. The immutable design and decentralized consensus methods of blockchain make sure that data is safe and correct where it starts. The study outlines the use of blockchain to control access to the perception layer of IoT systems. We examine how smart contracts could enhance permission management by ensuring that only authorized individuals can access sensor data. This approach strengthens defenses by reducing dependence on vulnerable centralized systems. We also talk about how important edge and fog computing are in this situation. By moving data processing and storage closer to IoT devices, these solutions make the system more efficient and cut down on delay. By verifying local transactions, combining blockchain technology with fog and edge computing makes things faster and safer. Finally, we look at Proof of Stake (PoS) and Proof of Authority (PoA), two better decision mechanisms that can be used in IoT settings instead of the classic Proof of Work (PoW). These ways help IoT devices with limited resources by lowering their power needs and making them easier to expand. They make transaction approval quick and simple while keeping the network safe and secure. This paper discusses the positive and negative points of using blockchain technology in the Internet of Things. This will help researchers and writers prepare for the future.