Quantum computers aim to perform computations at a fraction of the time taken by a classical system. This capability poses a threat to traditional cryptography methods based on mathematical functions irrespective of the complexity of the algorithm followed for the implementation. Quantum key distribution (QKD) exists as a solution to ensure data security in quantum systems following the principle of quantum mechanics. However, there is still a need for a system that could perform QKD with few errors at longer distances, at lower cost, and yet easy to implement. Coherent one-way (COW)protocol offers such possibilities. Multiple modules for COW-QKD were designed and developed on a Xilinx Kintex board and integrated with optical and electronic components to form a system that could demonstrate quantum key distribution at a sifted key rate of 2 kbps over a 105 km fiber, and achieve a quantum bit error rate (QBER) of 11.6 %.