Proceedings

EPJ D Highlight - Better safeguards for sensitive information

Schema of the encryption channel.

Study improves the lower boundary and secret key capacity of an encryption channel

The secure encryption of information units based on a method called quantum key distribution (QKD) involves distributing secret keys between two parties - namely, Alice, the sender, and Bob, the receiver - by using quantum systems as information carriers. However, the most advanced quantum technology, QKD, is currently limited by the channel's capacity to send or share secret bits. In a recent study published in EPJ D, Gan Wang, who is affiliated with both Peking University, Bejing, China, and the University of York, UK, and colleagues show how to better approach the secret key capacity by improving the channel's lower boundary.

The first stage of a QKD transmission is monitored by an eavesdropper, named Eve, as Alice and Bob share a raw key. However, Eve does not have access to a perfect copy of the signals sent by Alice due to quantum rules. During the second stage, Alice and Bob follow classical protocols involving the correction of errors and enhancement of privacy levels. Thus, Alice and Bob share a complete secret key that can later be used to send confidential messages.

The authors focus on a particular type of channel, called the noisy thermal amplifier channel, where the input signals are amplified together with noise induced by the thermal environment. The authors calculate the highest-known amount of secret information units, or bits, that Alice and Bob can share via such a channel. This is done by injecting controlled noise—made up of well-defined thermal agitation—into the detection apparatuses. By optimizing over this noise, they improve the lower boundary of the capacity in the amplifier channel. The authors also confirm that the distribution of secret keys over this channel may occur at higher rates than the transmission of quantum information itself.

I thank you very much for the patient and efficient support for technical and administrative assistance given me during the preparation of the necessary material for the publication of proceedings . The complete procedure for the publication took place in a short time by the organization of EPJ Web of Conferences, and I hope that the results of our Symposium can meet a wide interest from the scientific community working in the field of physics of mesons.

Giorgio Giardina, Messina University - INFN Catania, Italy
Co-editor EPJ Web of Conferences vol. 72, 2014

ISSN: 2100-014X (Electronic Edition)

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