Smart meters are playing critical roles in state grid construction. To secure the safety information communication from/to smart meters, this paper presents a novel high-security cryptographic system and its application in smart meters. This cryptographic system is mainly based on elliptic curve cryptography, and it is developed through a bottom-up approach to achieve optimal implementation. After its structural designing, this system is then simulated on a field programmable gate array device, and it is found that the proposed system has excellent performance. The proposed cryptographic system is also employed in the smart meters for further testing. The practical testing shows that the proposed cryptographic system has significantly performance in data security with smart meters. It is shown that the proposed system can be extended further for practical usage because of its high security performance.