Túl hatékonyak a képfelismerő technológiák?

Mivel az ember sokkal jobb mozgóképek felismerésében, mint a gépek, mozgó tárgyak jelenthetik a CAPTCHA-k újabb, a jelenlegieknél sokkal biztonságosabb generációját.

We see the popular "captcha" security mechanism often — wavy letters websites ask us to type into a box. It's used by web pages and newsletter sign-up forms to prevent computer robots from hacking into servers and databases. But these codes, which are becoming increasingly complicated for an average person to use, are not immune to security holes. A research project led by Prof. Danny Cohen-Or of Tel Aviv University demonstrates how a new kind of video captcha code may be harder to outsmart. The foundation of the work is really pure research, but it opens the door so security researchers can think a little differently. "Humans have a very special skill that computer bots have not yet been able to master," says Cohen-Or. "We can see what's called an 'emergence image' — an object on a computer screen that becomes recognizable only when it's moving — and identify this image in a matter of seconds. While a person can't 'see' the image as a stationary object on a mottled background, it becomes part of our gestalt as it moves, allowing us to recognize and process it." In the new research paper, co-authored with colleagues Cohen-Or describes a synthesis technique that generates pictures of 3-D objects, like a running man or a flying airplane. This technique, he says, will allow security developers to generate an infinite number of moving "emergence" images that will be virtually impossible for any computer algorithm to decode. Emergence," as defined by the researchers, is a unique human ability to collect fragments of seemingly useless information, then synthesize and perceive it as an identifiable whole. So far, computers don't have this skill. Computer vision algorithms are completely incapable of effectively processing emergence images. The scientists warn that it will take some time before this research can be applied in the real world, but they are currently defining parameters that identify the "perception difficulty level" of various images that might be used in future security technologies. "We're not claiming in our research paper that we've developed a whole new captcha technology," says Prof. Cohen-Or. "But we are taking a step towards that — something that could lead to a much better captcha, to highlight the big difference between men and bots.

IT3 komment: A képfelismerő technológiák határozottan sokat fejlődtek az elmúlt két évtizedben. Legalábbis ezt látszik alátámasztani az a tény, hogy a két dimenziós capthcha-k egyre kevésbbé alkalmasak arra, hogy távol tartsák a weboldalaktól a rosszindulatú (ro)botokat. A Tel-Aviv Egyetemen fejlesztett emergens, három dimenziós képalkotó algoritmusok alkalmasak lehetnek a "túlságosan fejlett" két dimenziós képfelismerő technológiák okozta biztonsági problémák kezelésére is. Természetesen csak addig, amíg ki nem fejlesztik az emergens, háromdimenziós képek felismerését is lehetővé tevő megoldásokat.

Forrás: www.aftau.org