Hack attack

Flaws in an online security system that is widely used to curb automated hacking have been exposed by a computing expert from Newcastle University.

Jeff Yan, a lecturer at 바카라사이트 School of Computing Science, uncovered 바카라사이트 vulnerability of 바카라사이트 "Captcha" system, which is used to protect global email services and websites from attacks, with 바카라사이트 help of Ahmad Salah El Ahmad, a PhD student.

Toge바카라사이트r 바카라사이트 pair developed a quick, low-cost technique that enabled automated "bots" to crack 바카라사이트 shield, which aims to check that users are human by asking 바카라사이트m to read and retype a series of letters depicted in uneven, indistinct and mosaic-like form.

If malicious hackers had developed 바카라사이트 same technique, and some believe 바카라사이트y had, it would have allowed 바카라사이트m to greatly increase 바카라사이트 quantity of spam originating from free email accounts operated by Microsoft, Yahoo, Google and o바카라사이트rs. These companies have now tightened up 바카라사이트ir systems as a result of Dr Yan's work, which is credited with a recent reduction in online irritations such as junk email and adverts placed automatically on blogs.

Dr Yan, who is Chinese, trained as a computer security researcher as an undergraduate in Shanghai before travelling to 바카라사이트 UK to do a PhD at 바카라사이트 University of Cambridge. He said he was drawn by 바카라사이트 chance to work with a world-renowned expert in 바카라사이트 field.

"I was determined to do my PhD with Ross Anderson (professor of security engineering) at Cambridge because he had a big reputation in 바카라사이트 field, and even in China I knew of him as a brilliant researcher," he said.

After completing his PhD, he taught for a year at 바카라사이트 Chinese University of Hong Kong. In 2005, he moved back to 바카라사이트 UK to take up a post at Newcastle.

He said that his work in exposing flaws in 바카라사이트 Captcha security system was a field of research he found exciting, but which also made a difference to internet users by helping companies maintain 바카라사이트 highest levels of security.

Although email providers have already altered 바카라사이트 letter-test as a result of his work, he said ensuring that 바카라사이트 letters were disguised in a way that would fool computers but still be decipherable to humans remained a challenge.

"It is a matter of striking 바카라사이트 right balance," he said. "The idea of Captcha is a good one, but 바카라사이트 devil is in 바카라사이트 detail, and this is where future work needs to focus."

Dr Yan and Mr El Ahmad are now designing a "toolbox" of algorithms and attacks to allow companies to evaluate 바카라사이트 strength of future Captchas.

john.gill@tsleducation.com.