With the rapid advancement of wireless technologies, distinct futuristic applications of Wireless Sensor Networks (WSNs) are evolving for both public and private domains. However, Wireless Sensor Nodes experience the major challenges in terms of power supply, computing capabilities and bandwidth requirements during the data communication. Apart from these, data confidentiality and integrity suffer due to various transmission errors caused by channel noise, channel bandwidth limitation, weak signals, limitation of transmitting and receiving devices as well as different security attacks. Various researches have been conducted to resolve these issues in an integrated way. Nevertheless, existing literature does not offer any effective solution to resolve these issues. Hence, this paper proposes a unique Elliptic Curve based Cryptography along with the Diffie-Hellman key exchange technique to address these issues. The experimental results show that the proposed technique consumes low power and utilizes CPU time effectively by offering better throughput and low Cyclomatic Complexity. It enhances confidentiality by producing higher avalanche effect and entropy value than the existing techniques. The capacity of generating higher Signal to Noise Ratio and lower percentage of Information Loss justify its efficiency to produce higher data integrity as compared to the existing schemes in the literature.