— Because of limited resources at sensor nodes, sensor networks typically adopt symmetric-key algorithms to provide security functions such as protecting communications between nodes. In order to use symmetric-key algorithms, two nodes need to establish a secret session key first. In this paper, we propose a novel chord-based key establishment (CBKE) protocol that allows any pair of nodes in a sensor network to establish a secret session key. CBKE is a generalized deterministic key establishment scheme that provides great flexibility for balancing memory overhead, reliability, and communication cost. We analyze the properties of CBKE and explore the performance tradeoffs using simulation.