The Internet of Things (IoT) has become a field with enormous potential, effect, and development with the emergence of smart cities, smart houses, and intelligent objects. Computer Information System Company (Cisco Inc). Projects that there will be 51 billion devices which are connected by 2021. However, the majority of those IoT gadgets are simple to alter and attack. These IoT devices are generally more susceptible to assaults than other types of endpoints such as desktops, mobile phones, or tablets because of their limitations in terms of storage, computing, and networking capability. The main IoT security concerns are presented and addressed in this study. Along with the methods utilized for connection, interaction, and administration, we examine and classify common security concerns about the IoT layers of architecture. In addition to the most recent assaults, challenges and innovative approaches, we describe the security necessities of the IoT. In addition, we connect and tabulate IoT safety problems with current literature-based remedies. Above all, we explore that blockchain technology, the software that powers Bitcoin, can play a major role in enabling the resolution of numerous IoT security issues. Difficulties along with unresolved research issues related to IoT security are also listed in this study.