Building smart services for smart cities has become a significant focus of the Internet of Things (IoT). These IoT devices are able to sense their surroundings and react appropriately. Smart city applications emphasize the necessity of safe data sharing across heterogeneous devices. Certain behaviors taken while sharing could aim at compromising security, privacy, and integrity. The centralized repository that is currently in place made the majority of hacks possible. The sharing of sensitive data and authentication are essential stages in guaranteeing the security of applications associated with IoT. Blockchain and IoT are two widely used technologies, with IoT focusing on data collection via various devices and blockchain enabling data integrity. This paper introduces a novel blockchain-based framework to ensure the security and integrity aspects of IoT data. The proposed SecPrivPreserve framework ensures security through various phases including initialization, registration, data protection, authentication, data access control, validation, and data sharing and download. Diverse security mechanisms such as passwords (OTP), encryption, and hashing have been deployed in various phases to strengthen security merits confidentiality, privacy, and integrity. Since the SecPrivPreserve framework is simulated in a permissioned blockchain platform the merits and tamper-proof and non-repudiation are automatically considered. Moreover, data protection uses Chebyshev polynomials and interpolation. The presented framework has experimented with Fabric SDK. The experimental results of the proposed framework are compared with the BaseLine state-ofthe-frameworks, The experimental analysis reveals that the proposed SecPrivPreserve approach achieved 34 Sec improvement in terms of responsiveness 94 Sec as computational time, encryption quality as 0.87 Sec and 0.82 Sec for detection rate.
