An algorithm for the illegal copying detection of digital documents

Document copy detection has very important application in both intellectual property protection and information retrieval. In this paper, a novel reconstruction method and the corresponding overlap measuring algorithm based on the thought of mathematical expression is presented. Firstly, the documents are expressed in the aspect of component granularities; and then the text attribute vector space model was established according to the statistic of component frequencies; after that, the overlap value is obtained. Results of experiments showed that the algorithm is available.