Numerous authentication schemes have been proposed in the past to protect communication authenticity and integrity in wireless sensor networks. Most of them, however, have one or several of the following limitations: high overhead in computation or communication overhead, no resilience to a large number of node compromises, delayed authentication, lack of scalability, etc. To address these issues, this talk will introduce a novel message authentication approach. This approach adopts a perturbed polynomial-based technique to simultaneously accomplish the goals of lightweight, resilience to a large number of node compromises, immediate authentication, scalability, and non-repudiation. In the talk, several preliminary schemes will be discussed in a stepwise manner before the final solution is presented.