The use of wireless sensor networks (WSNs) in any real-world application requires a certain level of security. To provide security of operations such as message exchange, key management schemes have to be well adapted to the particularities of WSNs. This paper proposes a novel key management scheme called SKM for sequence-based key management in WSNs. In SKM, sensor nodes are pre-distributed with the first term and the recursive formula of a numerical sequence. This two tiny pre-distributed information will ensure the establishment of pairwise keys to each sensor node with its neighbors after its deployment with a small amount of computation. The security analysis of SKM shows its efficiency. Simulation results confirm that SKM is lightweight in term of node’s resources and has a good resilience against node compromising attacks compared to the main existing schemes.