1,575 research outputs found
Measurement-device-independent quantum key distribution over untrustful metropolitan network
Quantum cryptography holds the promise to establish an
information-theoretically secure global network. All field tests of
metropolitan-scale quantum networks to date are based on trusted relays. The
security critically relies on the accountability of the trusted relays, which
will break down if the relay is dishonest or compromised. Here, we construct a
measurement-device-independent quantum key distribution (MDIQKD) network in a
star topology over a 200 square kilometers metropolitan area, which is secure
against untrustful relays and against all detection attacks. In the field test,
our system continuously runs through one week with a secure key rate ten times
larger than previous result. Our results demonstrate that the MDIQKD network,
combining the best of both worlds --- security and practicality, constitutes an
appealing solution to secure metropolitan communications.Comment: 17 pages, 4 figure
Practical challenges in quantum key distribution
Quantum key distribution (QKD) promises unconditional security in data
communication and is currently being deployed in commercial applications.
Nonetheless, before QKD can be widely adopted, it faces a number of important
challenges such as secret key rate, distance, size, cost and practical
security. Here, we survey those key challenges and the approaches that are
currently being taken to address them.Comment: To appear in npj Quantum Informatio
Experimental measurement-device-independent quantum digital signatures over a metropolitan network
Quantum digital signatures (QDS) provide a means for signing electronic
communications with informationtheoretic security. However, all previous
demonstrations of quantum digital signatures assume trusted measurement
devices. This renders them vulnerable against detector side-channel attacks,
just like quantum key distribution. Here, we exploit a
measurement-device-independent (MDI) quantum network, over a
200-square-kilometer metropolitan area, to perform a field test of a
three-party measurement-device-independent quantum digital signature (MDI-QDS)
scheme that is secure against any detector side-channel attack. In so doing, we
are able to successfully sign a binary message with a security level of about
1E-7. Remarkably, our work demonstrates the feasibility of MDI-QDS for
practical applications.Comment: 5 pages, 1 figure, 2 tables, supplemental materials included as
ancillary fil
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