Quantum communication is a method of transmitting information using the principles of quantum mechanics. It relies on the behavior of particles, such as photons, which can exist in multiple states at once. This allows for secure communication, as any attempt to intercept the information changes the state of the particles, alerting the sender and receiver. One of the key techniques in quantum communication is quantum key distribution (QKD). QKD enables two parties to generate a shared, secret key that can be used for encrypting messages. This technology is considered highly secure, as it leverages the unique properties of quantum systems to protect against eavesdropping.