Researchers are exploring the use of blockchain technology to enhance security in various networks, including 6G cognitive radio IoT networks. Studies are investigating the integration of blockchain with other technologies, such as artificial intelligence and quantum deep learning, to improve security in areas like healthcare, energy, and maritime applications. The surveys and reviews cover a range of topics, including secure data migration, intrusion detection, and bandwidth allocation, but it is unclear how these advancements will be applied specifically to 6G cognitive radio IoT networks.