Quantum cryptography, a new technology until now considered 100 percent secure against attacks on sensitive data traffic, has a flaw after all, Swedish researchers said Friday.

“In computer terms, we’ve found a bug,” said Jan-Aake Larsson, an associate professor of applied mathematics at the Linkoeping University in southern Sweden.

“It was surprising,” he told AFP.

“We didn’t expect to find a flaw,” he said, adding that he and another researcher at the university had also discovered a way to fix the problem.

Many experts hope quantum cryptography will be the answer to growing fears about data security on the Internet, providing a one-off code that would be unbreakable for hackers.

Most sensitive data like money transactions have to date been transmitted over the Internet using a so-called public key, which is considered safe because it consists of a string of some 2,000 data bits and requires enormous calculations to break.

An evolving technology called quantum cryptography has meanwhile emerged as absolutely secure since quantum mechanical objects, according to the laws of physics, cannot be measured upon without being disturbed and setting off alarm bells that the transmitted data has been manipulated.

“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,” a statement from Linkoeping University explained.

The technology, which requires special hardware, is considered absolutely airtight and is widely expected to revolutionise the field of secure data transmission.

At the moment, however, quantum cryptography is limited to short-range transmissions and is so pricey that only a handful of banks and businesses have so far begun testing the system.

Contrary to current convictions, Larsson said he and his student Joergen Cederloef had discovered a weakness in the supposedly flawless technology.

To send the key over the quantum channel, you must simultaneously send additional data over the traditional Internet channel, and then verify that the classical data has not been changed through an authentication process, he explained.

While all data traveling though the quantum channel was 100 percent secure, “a gap appears because this is a combined system, which complicates things so much that the usual security system in some cases does not work,” Larsson said.

The problem arises when the system had been running for a long period of time, he said, adding that he and Cederloef proposed adding a so-called handshake between legitimate users.

“All that’s needed is a small addition to the authentication process to fill the security gap,” Larsson said.

Google has seen an acceleration of  Internet activity among mobile phone users in recent months since the company has introduced faster Web services on selected phone models, fuelling confidence the mobile Internet era is at hand, the company said on Tuesday.

“We have very much hit a watershed moment in terms of mobile Internet usage,” Matt Waddell, a product manager for Google Mobile, said in an interview. “We are seeing that mobile Internet use is in fact accelerating.

The growing availability of flat-rate data plans from phone carriers instead of per-minute charges that previously discouraged Internet use, along with improved Web browsers on mobile phones as well as better-designed services from companies like Google are fuelling the growth, Waddell argued.

Google made the pronouncement as it introduced a new software download for mobile phones running Microsoft’s Windows Mobile software that conveniently positions a Google Web search window on the home screen of such phones.

Similar versions of the search software which Google introduced for Blackberry users in December and certain Nokia phones in February have sped up the time users take to perform Web searches by 40 percent and, in turn, driven usage.

The software shortcuts the time it takes for people to perform Web searches on Google by eliminating initial search steps of finding a Web browser on the phone, opening the browser, waiting for network access, and getting to Google.com. By making a Google search box more convenient, mobile phone users have begun using the Internet more, the company said.

“We are actually seeing a 20 percent increase in the number of searches by people,” Waddell said.

Google’s mobile plug-in software lets users customize their phones to feature Google mobile services instead of relying solely on software features network carriers have pre-installed on the devices.

“Faster is better than slow, especially on a mobile device, where fast is much better than slow,” Waddell said. “Not only are we are seeing increased user satisfaction but also greater usage.”

Microsoft expects to have sold 20 million Windows Mobile devices by the end of its fiscal year in June, which together with Blackberry and Symbian-based phones represent upward of 85 percent of the Internet-ready smartphones sold in the world.

Users of phones based on software from Research in Motion, Nokia’s Symbian-based phones and now Microsoft Windows Mobile can download the software at http://mobile.google.com/.

Google officials said in August that they had seen a similar surge in usage of Google.com via mobile devices following the launch of the Apple iPhone last year. The iPhone offers a full-featured Internet browser unlike many phones.

Waddell said Google had seen iPhone users perform as many as 50 times more Web searches on these computer-phone devices as users of standard mobile feature phones typically do.