Quantum Key Distribution (QKD) is a secure method of sharing encryption keys between two parties by utilizing the principles of quantum mechanics. It ensures that any attempt to intercept or eavesdrop on the key exchange is immediately detectable, as the act of measuring quantum data alters its state. This makes QKD highly secure and ideal for protecting sensitive communications. One common implementation of QKD is through photons transmitted over fiber-optic cables, where their quantum states encode the key. QKD is often seen as a foundation for next-generation secure communication systems.