Communicating covertly goes quantum

Sending undetected messages possible with qubits, new study suggests

Coded messages can keep your secrets safe, but you also might prefer to conceal the fact that you’re communicating at all. Now, scientists are working to make even the whispers of top-secret communications completely undetectable by eavesdroppers. And the methods for sending such stealthy dispatches are being extended from ordinary “classical” messages to quantum ones.