Marcin Urbanski

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Modern malware uses advanced techniques to hide from static and dynamic analysis tools. To achieve stealthiness when attacking a mobile device, an effective approach is the use of a covert channel built by two colluding applications to exchange data locally. Since this process is tightly coupled with the used hiding method, its detection is a challenging(More)
In this paper we present a new CAPTCHA system (Completely Automated Turing Test To Tell Computers and Humans Apart). This proposal, SemCAPTCHA, is motivated by an increasing number of broken OCR-based CAPTCHA systems and it is based not only on text recognition but also on text understanding. We describe SemCAPTCHA from both user's perspective and system's(More)
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