One of the most essential methods used to provide security services is encryption. One key is used for encoding in symmetric encryption. The symmetric encryption depends on the encryption block, switching, and replacing. Therefore, it is a problem if the received secret keys from protocols are frequents in some states or they have less randomness. In this paper, a Light Weight Multiple Key Generating (LWM) is proposed to generate the secret keys which are using Light Weight Schemes (LWS). In this work, six experiments are implemented. Three LWA are utilized, which are Xtea, RC5, and Tea algorithms. The SHA2 hash function is used to merge the chains. The diehard test is used in all experiments to determine the randomness of the secret key produced. The entropy is a measure of the uncertainty of a random variable.

Wireless sensor network (WSN) security is an important component for protecting data from an attacker. For improving security, cryptography technologies are divided into two kinds: symmetric and asymmetric. Therefore, the implementation of protocols for generating a secret key takes a long time in comparison to the sensor’s limitations, which  decrease network throughput because they are based on an asymmetric method. The asymmetric algorithms are complex and decrease network throughput. In this paper, an encryption symmetric secret key in wireless sensor networks (WSN) is proposed. In this work, 24 experiments are proposed, which are encryption using the AES algorithm in the cases of 1 key, 10 keys, 25 keys, and 50 keys. In each experiment, two chains are combined by using a hash function (SHA-2) to produce secret keys. The Network Simulator Version 2 (NS2) was used to assess the network throughput for the generated key. The randomness of the suggested LWM method has been tested by using the Diehard statistical test and the Entropy test. The results of the tests show that the encryption secret keys have a high level of data randomness.