In secure communication key management plays an important role. Ensuring of security and trust worthiness in any transmission taking place via Wireless Sensor Networks (WSN) can be done using thoughtfully designed key management models. Here, the method of clustering is used to increase
the system performance. Also, an effective key generation method is proposed for secured data transmission for the clustered wireless sensor networks. This method uses Chinese Remainder Theorem (CRT) for generating secret key for each cluster and merges with cluster head ID to generate a unique
144-bit encryption keys. Since, CRT uses random numbers for generating keys, separate active keys that are dynamic to ensure secured data transmission. The proposed model provides a positive impact by improving the lifetime, reducing the delay time, memory requirements and energy consumption,
when compared with other existing state of art methods. Moreover, it protects data from brute-force attack, forward as well as backward secrecy and node compromised attack.