Abstract : The Leap scheme is a classic key management scheme for wireless sensor networks. However, it has a drawback: once the initialization key is leaked, the security of other nodes in the entire wireless sensor network is threatened. Jang et al. proposed an improved scheme based on the Leap scheme, which greatly reduces the threat caused by the leakage of the initialization key. This paper proposes a timestamp-based wireless sensor key management scheme based on the Jang scheme and analyzes the security and execution efficiency of the proposed scheme. Compared with the Jang scheme, this scheme has better security and solves the threat caused by the leakage of the initialization key, while keeping the computational and storage costs the same and the communication costs slightly higher. Keywords : Wireless sensor network; key management; timestamp; time slot; pairing key 1. Introduction Wireless sensor networks (WSNs) are composed of many low-cost sensors, each with limited computing power, limited energy, and limited storage space. They can be widely used in education, military, medical, transportation and other fields, and have become one of the hot research topics at home and abroad in recent years. Ensuring the security of the entire network is particularly important when WSNs are deployed in environments that are untouched, vulnerable, or easily captured, especially in military deployments in enemy environments. A full text download of a timestamp-based wireless sensor key management scheme is also available.