In a wireless sensor network (WSN), all detected data is delivered via a wireless communication channel to a sink node, then sent to an information-gathering centre for necessary actions or controls. The sensed data could be readily manipulated or eavesdropped on if security procedures are not used. For WSN, several security solutions based on classical cryptography have been devised, although the sophisticated encryption operations take significant energy. The symmetric and asymmetric key encryption provides efficient data security, but it takes high energy consumption and computational complexity. In this paper, a lightweight, energy-efficient secure text encryption is proposed using the dynamic salt key. There are three primary processes in the suggested paradigm. The first is salt generation. The next step is to encrypt secret text using format-preserving encryption based on the salt key, and the final step is to decrypt the data. The encryption process is more secure, and the hackers cannot capture key values. The proposed approach creates a safe environment for sensors to protect the data quickly, efficiently, and low-computation before sending it across a wireless network to the sink node. The proposed method simulation provides a high level of security while requiring minimal communication and computational resources.