Abstract
Zero-day attacks, new (anomalous) attacks exploiting previously unknown system vulnerabilities, are a serious threat. Defending against them is no easy task, however. Having identified degree of system knowledge as one difference between legitimate and illegitimate users, theorists have drawn on information theory as a basis for intrusion detection. In particular, Kolmogorov complexity (K) has been used successfully. In this work, we consider information distance (Observed/spl I.bar/K - Expected/spl I.bar/K) as a method of detecting system scans. Observed/spl I.bar/K is computed directly, Expected/spl I.bar/K is taken from compression tests shared herein. Results are encouraging. Observed scan traffic has an information distance at least an order of magnitude greater than the threshold value we determined for normal Internet traffic. With 320 KB packet blocks, separation between distributions appears to exceed 4/spl sigma/.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
