Feeds

Quantum crypto boffins in successful backdoor sniff

Erroneous error-handling undermines bulletproofness

Build a business case: developing custom apps

Computer scientists have pulled off what is claimed to be the first successful attack against a commercial system based on theoretically uncrackable quantum cryptography.

Quantum key exchange, which forms the basis of quantum cryptography, relies on a principle of quantum physics that means it is not possible to eavesdrop on single quanta - generally photons in an optical fibre - without changing their state. Alterations would be detected as errors, immediately alerting the intended recipient of a key that there's a problem. When properly implemented, quantum key distribution/exchange offers bullet-proof security.

In practice, however, it is not possible to completely eliminate errors in electronic communications because of factors such as noise and signal degradation. So practical systems accept key exchanges where the error rate is less than 20 per cent.

Feihu Xu, Bing Qi and Hoi-Kwong Lo at the University of Toronto in Canada have developed a subtle "intercept and resend attack" where they eavesdrop on some of the quantum bits sent during a quantum key exchange but not so many as push the error rate over the 20 per sent threshold. The boffins demonstrated such a "phase remapping" attack against commercial quantum cryptography systems from ID Quantique.

As the boffins explain, their attack takes advantage of the mistaken assumption that the sender can prepare the required quantum states without errors.

The ID Quantique system is not broken, they say, but requires tweaking to get over the unsafe assumption that error rates of less than 20 per cent must be due to noise and can be safely disregarded. The attack, as is so often the case in the history of the battle between code makers and code breakers, is an implementation weakness rather than a systemic one.

The work of the Canadian team follows lab-based attacks on quantum crypto set-ups that relied on exploiting internal reflections in kit that generates quantum bits, or the interception of stray photons between detectors and lasers to eavesdrop on supposedly secure communications channels. The Canadian team's paper, Experimental demonstration of phase-remapping attack in a practical quantum key distribution system, can be found here.

A summary of their work can be found in a story by Technology Review here. ®

Endpoint data privacy in the cloud is easier than you think

More from The Register

next story
14 antivirus apps found to have security problems
Vendors just don't care, says researcher, after finding basic boo-boos in security software
'Things' on the Internet-of-things have 25 vulnerabilities apiece
Leaking sprinklers, overheated thermostats and picked locks all online
iWallet: No BONKING PLEASE, we're Apple
BLE-ding iPhones, not NFC bonkers, will drive trend - marketeers
Multipath TCP speeds up the internet so much that security breaks
Black Hat research says proposed protocol will bork network probes, flummox firewalls
Only '3% of web servers in top corps' fully fixed after Heartbleed snafu
Just slapping a patched OpenSSL on a machine ain't going to cut it, we're told
Microsoft's Euro cloud darkens: US FEDS can dig into foreign servers
They're not emails, they're business records, says court
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Israel's Iron Dome missile tech stolen by Chinese hackers
Corporate raiders Comment Crew fingered for attacks
prev story

Whitepapers

7 Elements of Radically Simple OS Migration
Avoid the typical headaches of OS migration during your next project by learning about 7 elements of radically simple OS migration.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Solving today's distributed Big Data backup challenges
Enable IT efficiency and allow a firm to access and reuse corporate information for competitive advantage, ultimately changing business outcomes.
A new approach to endpoint data protection
What is the best way to ensure comprehensive visibility, management, and control of information on both company-owned and employee-owned devices?