Quantum Key Distribution (QKD) is a method of key exchange between the communicating entities with security guaranteed by the fundamental rules of quantum mechanics, that helps to detect any attempt of eavesdropping by changing the system properties irreversibly during any intrusion. With the rapid advancements in quantum computing, the security of the existing cryptographic methods, that is based on computationally hard problems, will be at stake. In 1984 Charles Bennett and Gilles Brassard proposed the first QKD protocol, known as BB84. Differential-Phase Shift (DPS) and Coherent One-Way (COW) QKD protocols have gained popularity due to the high key rate and ease of practical implementation. Although QKD offers information-theoretic security, imperfections in devices are exploited for side-channel attacks. The transmitter can be protected by using an isolator. Measurement Device-Independent (MDI) QKD protocol eliminates chances of detector-side side-channel attacks and offers perfect security. The QKD nodes, commonly known as Alice and Bob, are connected through a quantum channel reserved for qubit transmission and a classical channel reserved for synchronisation and other post-processing tasks. Key generation involves multiple steps−Classical channel authentication, qubit transmission and synchronisation, sifting, error correction, and privacy amplification. Standard development organisations like ETSI and ITU-T are developing standards for QKD. However, existing QKD solutions are mostly vendor proprietary with a limited scope of interoperability. There is a scope for the development of open and standard interfaces among different horizontal as well as vertical layers of the quantum communication network stack. The potential use of the QKD system will be in strategic communication among various government offices, military and defence networks, healthcare and pharmaceutical sectors, blockchains, banking, finance and insurance sectors, telecommunication and IT networks