Edge data security became the crucial concern of the network connected framework. It demands for the lightweight solutions where the traditional algorithms have not been suitable for the resource constrained devices. Hence, the development of lightweight crypto-solutions has attained the visibility. This proposed leverages the traditional Lightweight Encryption Algorithm (LEA) on reconfigurable hardware such as Field Programmable Gate Array (FPGA) by addressing its potential pitfalls namely vulnerable to differential cryptanalysis. To overcome this, 5-bit Substitution box (S-box) blended with chaos approach has been adopted on the traditional LEA schema. Which also ensures the lightweightness. The substitution and chaotic diffusion processes improves the strength of the LEA to meet out the statistical requirements which was confirmed by conducting the NIST SP 800 – 22 batteries of test by attaining the pass rate of 99.9%with the level of significance as 0.01. Further, Hamming distance and Shannon entropy were estimated to determine the switching activity and uniformity of the generated randomness. On the other hand, the modified LEA occupies only less than 5% of the total hardware footprint of the Intel Cyclone IV E FPGA chip which dissipates 131.62 mW of power for encryption and 132.27 mW of power for decryption respectively. The obtained results were compared with the traditional LEA design and it evidences that the modified LEA with S-box and chaos has significantly increased the performance.