Quantum key distribution (QKD) allows two remote parties to grow a sharedsecret key. Its security is founded on the principles of quantum mechanics, butin reality it significantly relies on the physical implementation.Technological imperfections of QKD systems have been previously explored, butno attack on an established QKD connection has been realized so far. Here weshow the first full-field implementation of a complete attack on a running QKDconnection. An installed eavesdropper obtains the entire 'secret' key, whilenone of the parameters monitored by the legitimate parties indicate a securitybreach. This confirms that non-idealities in physical implementations of QKDcan be fully practically exploitable, and must be given increased scrutiny ifquantum cryptography is to become highly secure.
展开▼
