+-----------------+ | End User | | | +-----------------+ ^ | Local Secure Interface | (e.g., the same physical hardware | or a local secure network) | +------------------+-------------------+ | | | | V V +----------------+ /--------\ +----------------+ | |--->( Quantum )--->| | | | ( Internet ) | | | Quantum | \--------/ | Quantum | | Computer A | | Computer B | | (e.g., Site #1)| /--------\ | (e.g., Site #2)| | | ( Classical) | | | |<-->( Internet )<-->| | +----------------+ \--------/ +----------------+