The growing number of IoT devices, microtransaction security in the Internet of Things (IoT) is a critical issue. In order to improve the security of microtransactions in Internet of Things ecosystems, this article investigates the usage of cryptographic primitives. Strong safeguards against possible risks including data manipulation, eavesdropping, and unauthorized access are provided by cryptography, which provides a foundation for guaranteeing the confidentiality, integrity, and validity of transaction data. We address the special problems of power and processing limits by delving into the implementation of lightweight cryptography algorithms and protocols designed for resource-constrained IoT devices. Our goal is to create a trust framework that guarantees the security and privacy of data exchange by incorporating cryptographic primitives into IoT microtransactions. By encouraging trust and dependability in microtransactions, which are essential to the future of networked smart devices, our research helps to build a more secure and robust Internet of Things environment.