Sensor nodes in wireless sensor networks have limited resources such as computing power, storage space, and battery life. Since WSNs are often deployed in untrusted areas, they are vulnerable to a wide variety of threats. Given the impossibility of preventing security breaches in a WSN, its data quality is likewise called into doubt. The authentication method in WSNs allows for the verification of the authenticity of both resources and data. Authentication in WSNs safeguards the integrity of the original data by determining whether it came from a trusted source and only allowing modifications made by that source. Existing authentication systems, however, have certain security flaws, such as those vulnerable to Identity (ID) spoofing attacks. As another example of promising new technology, blockchain has shown great promise in the realm of cyber security. The blockchain's security features include its cryptographic protection, immutability, non-reputability, irrevocability, auditability, and verifiability. This research is motivated by a desire to implement blockchain capabilities in WSNs for data integrity, security, and efficiency. In this study, research developed a new blockchain-based authentication method specifically for WSNs. Sensor nodes and a blockchain were built into the study's system architecture with the help of users and a private blockchain. A full security audit was done on the data used in the study. Concurrently, the proposed model was deployed to a wireless sensor node (WiSeN) sensor node to analyze its performance. According to the simulation findings, the suggested optimized strategy outperforms the traditional non-optimized technique in terms of accuracy. Furthermore, MVO has greater accuracy than ACO and PSO. The advantages of this technology and the issues with the present authentication processes make it imperative that the WSN deploy it. Optimization strategies are tested to improve security in WSNs. PSO, ACO, and MVO boost precision, recall, and F1-score. These procedures are trustworthy and might improve network resilience and counter real-world challenges. Security solutions may improve with further study.