Smart Grid systems are quickly transforming traditional electrical grids, incorporating digital communication, distributed energy resources, and advanced analytics for improved reliability, efficiency, and sustainability. However, this digital transformation also introduces new vulnerabilities related to data security, privacy, and integrity, especially during communications between grid components and control systems. Blockchain technology — with its decentralization, immutability, and cryptographic mechanisms — presents an innovative solution to secure data transmission within Smart Grid networks. This research proposes a Blockchain-Based Secure Data Transmission Framework (BSDTF) tailored for Smart Grid applications. The framework leverages permissioned blockchain, smart contracts, and Lightweight Cryptographic Protocols to enhance data security without significant computational overhead, which is critical for resource-constrained grid devices.

The article presents a detailed literature survey, system requirements and analysis, architectural design, implementation strategies, testing results, and future scope. Performance evaluations demonstrate significant improvements in data integrity, authentication, and resilience against common cyberattacks. Key contributions include a custom consensus mechanism suitable for Smart Grid environments and a hybrid encryption strategy that balances security with performance.

The proposed system architecture integrates modular components to enhance scalability and maintainability. Implementation leverages lightweight cryptographic algorithms to optimize computational efficiency without compromising security. Testing results validate the robustness of the approach under various attack scenarios, confirming its suitability for real-world Smart Grid applications.