An Efficient and Secure Group Rekeying Scheme for WSNs via Symmetric Polynomial Key Pre-Distribution

In wireless sensor networks (WSNs), establishing a robust key agreement is essential for securing communications. Various performance metrics are typically employed to evaluate these schemes, including storage requirements, communication overhead, and computational costs. Group key establishment ensures that sensitive information remains confidential, as only authorized nodes can decrypt broadcast messages. This paper proposes a group rekeying scheme based on symmetric polynomial key pre-distribution. By leveraging multivariable symmetric polynomials, a secure group key is constructed. Furthermore, the scheme incorporates a dynamic rekeying mechanism to update the group key whenever a sensor node is compromised, ensuring continuous forward and backward secrecy. Performance analysis demonstrates that the proposed scheme significantly reduces both communication overhead and computational complexity compared to existing methods.