IoT security is one of the prominent issues that has gained significant attention among the researchers in recent times. The recent advancements in IoT introduces various critical security issues and increases the risk of privacy leakage of IoT data. Implementation of Blockchain can be a potential solution for the security issues in IoT. This review deeply investigates the security threats and issues in IoT which deteriorates the effectiveness of IoT systems. This paper presents a perceptible description of the security threats, Blockchain based solutions, security characteristics and challenges introduced during the integration of Blockchain with IoT. An analysis of different consensus protocols, existing security techniques and evaluation parameters are discussed in brief. In addition, the paper also outlines the open issues and highlights possible research opportunities which can be beneficial for future research.

物联网安全是近年来引起研究人员高度关注的突出问题之一。物联网的最新进展引入了各种关键的安全问题，并增加了物联网数据隐私泄露的风险。区块链的实施可以成为物联网安全问题的潜在解决方案。本次审查深入调查了物联网中的安全威胁和问题，这些威胁和问题降低了物联网系统的有效性。本文对区块链与物联网集成过程中引入的安全威胁、基于区块链的解决方案、安全特征和挑战进行了明显的描述。简要讨论了不同共识协议、现有安全技术和评估参数的分析。此外，