How to beat a spammer

Spam messages are an incredible nuisance for most web users. But, now scientists claim to have developed an effectively "perfect" method for blocking the most common kind of spam, using spammers’ own trickery.

An international team, led by International Computer Science Institute in Berkeley and California University, has come up with a system that deciphers the templates a “botnet” is using to create spam. These templates are then used to teach filters what to look for, the ‘New Scientist’ reported. According to the scientists, the system works by exploiting a trick that spammers use to defeat email filters.

As spam is churned out, subtle changes are typically incorporated into the messages to confound spam filters. Each message is generated from a template that specifies message content and how it should be varied.

The team reasoned that analysing such messages could reveal the template that created them. And, since the spam template describes the entire range of the emails a bot will send, possessing it might provide a watertight method of blocking spam from that bot.

To test their idea, the team installed a previously captured software bot onto a machine. After analysing 1,000 emails generated by this compromised machine, less than 10 minutes’ work for most bots, the scientists were able to reverse-engineer the template.

Knowledge of that template then enabled filters to block further spam from that bot with 100% accuracy. The new system did not produce a single false positive when tested against more than a million genuine messages and the biggest advantage is this false positive rate, team member Andreas Pitsillidis said.

“This is an interesting approach which really differs by using the bots themselves as the oracles for producing the filters,” added Michael O’Reirdan , chairman of the messaging anti-abuse working group, a coalition of technology companies.

Apple's bookstore for iPad

Apple chief executive Steve Jobs announced on Wednesday the launch of an online bookstore dubbed "iBooks" for his company's new touchscreen tablet computer, the iPad.

"We've got five of the biggest publishers in the world supporting us and will open the floodgates for the rest of the publishers starting this afternoon," Jobs said at an event during which he unveiled the iPad.

"Amazon has done a great job of pioneering this functionality with the Kindle," Jobs said. "We are going to stand on their shoulders."

Apple unveils iPad tablet

Apple Inc Chief Executive Steve Jobs took the wraps off the "iPad" tablet on Wednesday, looking to define a new category of wireless device that will play video, games and all sorts of other media.

Jobs, who returned to the helm last year after a much-scrutinized liver transplant, is hoping to sell consumers on the value of tablet computing after numerous technology companies had failed to do so in recent years.

Called the "iPad," the device is Apple's biggest product launch since the iPhone three years ago, and arguably rivals the smartphone as the most anticipated in Apple's history.

After months of feverish speculation on the Internet and among investors, Jobs took the stage at a jam-packed theater in San Francisco and, with his famed showman's flair, began detailing the device's basic features. The iPad has a near life-sized touch keyboard and supports Web browsing.

It comes with a built-in calendar and address book, Jobs said. Technology enthusiasts had expected to see a sleek, full-color, 10-inch gadget with a touchscreen interface and wireless connectivity, designed for snacking on all sorts of media from videos to games to electronic books and newspapers.

Despite the buzz surrounding the launch and Apple's storied golden touch on consumer electronics, the tablet is not necessarily an easy sell, analysts say.

Consumer appetite for a gadget that sits somewhere between a smartphone and a laptop has yet to be proven, though plenty of devices such as Amazon.com's Kindle e-reader are vying for that market. Apple had been mum, so the market had been rife with speculation about the device. Shares of Apple have generally risen ahead of Wednesday's event.

The stock slipped on Nasdaq to about $201.67, still within reach of its all-time high of $215.59 logged on Jan. 5. As iPod sales wane, Apple is looking for another growth engine and hopes to find one in the tablet. But the move is not without risk. Consumers have never warmed to tablet computers, despite many previous attempts by other companies.