SmartSearch Steganalysis

摘要

There are two primary challenges to monitoring the Web for steganographic media: finding suspect media and examining those found. The challenge that has received a great deal of attention is the second of these, the Steganalysis problem. The other challenge, and one that has received much less attention, is the search problem. How does the steganalyzer get the suspect media in the first place? This paper describes an innovative method and architecture to address this search problem. The typical approaches to searching the web for covert communications are often based on the concept of "crawling" the Web via a smart "spider." Such spiders find new pages by following ever-expanding chains of links from one page to many next pages. Rather than seek pages by chasing links from other pages, we find candidate pages by identifying requests to access pages. To do this we monitor traffic on Internet backbones, identify and log HTTP requests, and use this information to guide our process. Our approach has the advantages that we examine pages to which no links exist, we examine pages as soon as they are requested, and we concentrate resources only on active pages, rather than examining pages that are never viewed.