Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Linköping University researchers break "unbreakable" crypto

15.04.2008
Quantum cryptography has been regarded as 100-percent protection against attacks on sensitive data traffic. But now a research team at Linköping University in Sweden has found a hole in this advanced technology.

The risk of illegal accessing of information, for example in money transactions, is necessitating more and more advanced cryptographic techniques.

When you send an encrypted message via the computer network, one of the most difficult problems to solve is how the key should be transmitted. One way is to send it by courier (either by regular mail or, as in spy movies, a person with a briefcase attached to his wrist). Another way is a "public key," which is used for online banking and security functions in Web browsers (https://).

A courier must of course be reliable, otherwise there is a risk that the key will be secretly copied on the way. A public key is regarded as secure, since enormous calculations are required to break the long strings of data bits - some 2,000 - that make up the key.

But a new technology called quantum cryptography is supposed to be absolutely secure. Thus far, however, very few people have made use of it. It requires special hardware, for example with a type of laser that emits polarized light particles (photons) via optic fiber or through the air. Some companies and banks in Austria are testing the system, and trials are underway with satellite-TV transmission.

The security is guaranteed by the laws of quantum mechanics.
Quantum-mechanical objects have the peculiar property that they cannot be measured upon or manipulated without being disturbed. If somebody tries to copy a quantum-cryptographic key in transit, this will be noticeable as extra noise. An eavesdropper can cause problems, but not extract usable information.

But Jan-Åke Larsson, associate professor of applied mathematics at Linköping University, working with his student Jörgen Cederlöf, has shown that not even quantum cryptography is 100-percent secure. There is a theoretical possibility that an unauthorized person can extract the key without being discovered, by simultaneously manipulating both the quantum-mechanical and the regular communication needed in quantum cryptography.

"The concern involves authentication, intended to secure that the message arriving is the same as the one that was sent. We have scrutinized the system as a whole and found that authentication does not work as intended. The security of the current technology is not sufficient," says Jan-Åke Larsson.

In the article, published in the prestigious journal IEEE Transactions on Information Theory, the authors propose a change that solves the problem.

"We weren't expecting to find a problem in quantum cryptography, of course, but it is a really complicated system. With our alteration, quantum cryptography will be a secure technology," says Jan-Åke Larsson.

Contact: Jan-Åke Larsson, phone: +46 (0)13-281468; e-mail: jalar@mai.liu.se

Åke Hjelm, | idw
Further information:
http://www.vr.se
http://expertsvar.se

More articles from Information Technology:

nachricht Chip-based devices improve practicality of quantum-secured communication
23.03.2020 | The Optical Society

nachricht Army scientists create quantum sensor that covers entire radio frequency spectrum
20.03.2020 | U.S. Army Research Laboratory

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

Im Focus: Stem Cells and Nerves Interact in Tissue Regeneration and Cancer Progression

Researchers at the University of Zurich show that different stem cell populations are innervated in distinct ways. Innervation may therefore be crucial for proper tissue regeneration. They also demonstrate that cancer stem cells likewise establish contacts with nerves. Targeting tumour innervation could thus lead to new cancer therapies.

Stem cells can generate a variety of specific tissues and are increasingly used for clinical applications such as the replacement of bone or cartilage....

Im Focus: Artificial solid fog material creates pleasant laser light

An international research team led by Kiel University develops an extremely porous material made of "white graphene" for new laser light applications

With a porosity of 99.99 %, it consists practically only of air, making it one of the lightest materials in the world: Aerobornitride is the name of the...

Im Focus: Cross-technology communication in the Internet of Things significantly simplified

Researchers at Graz University of Technology have developed a framework by which wireless devices with different radio technologies will be able to communicate directly with each other.

Whether networked vehicles that warn of traffic jams in real time, household appliances that can be operated remotely, "wearables" that monitor physical...

Im Focus: Peppered with gold

Research team presents novel transmitter for terahertz waves

Terahertz waves are becoming ever more important in science and technology. They enable us to unravel the properties of future materials, test the quality of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

MOC2020: Fraunhofer IOF organises international micro-optics conference in Jena

03.03.2020 | Event News

 
Latest News

3D printer sensors could make breath tests for diabetes possible

27.03.2020 | Power and Electrical Engineering

TU Bergakademie Freiberg researches virus inhibitors from the sea

27.03.2020 | Life Sciences

The Venus flytrap effect: new study shows progress in immune proteins research

27.03.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>