New power systems rely on renewable energy, smart grid operations, and market-driven mechanisms, bringing significant environmental and operational benefits. However, these advances also bring a series of security challenges, especially in terms of network vulnerabilities and potential attacks. This paper addresses these issues by proposing a lightweight Datagram Transport Layer Security (DTLS) mechanism. The mechanism is specifically designed for the unique needs of new power systems. The proposed approach simplifies the DTLS handshake process and integrates identity-based and attribute-based encryption, eliminating the need for certificate management and reducing datagram exchanges, achieving lower communication latency and overhead. In addition, the lightweight DTLS mechanism is synergistically combined with edge computing and deployed directly on the edge devices of the power system. This approach not only promotes secure end-to-end communication but also leverages the computing and storage capabilities of edge devices to enhance the overall network security performance to adapt to the dynamic and extended characteristics of modern power systems. This study contributes to the new endpoint security architecture and demonstrates the feasibility and effectiveness of the proposed solution in supporting a variety of power applications and strengthening the network security posture of the new power system.