A coding style-based plagiarism detection

In this paper a plagiarism detection framework is proposed based on coding style. Furthermore, the typical style-based approach is improved to better detect plagiarism in programming codes. The plagiarism detection is performed in two phases: in the first phase the main features representing a coding style are extracted. In the second phase the extracted features are used in three different modules to detect the plagiarized codes and to determine the giver and takers of the codes. The extracted features for each code developer are kept in a history log, i.e. a user profile as his/her style of coding, and would be used to determine the change in coding style. The user profile allows the system to detect if a code is truly developed by the claimed developer or it is written by another person, having another style. Furthermore, the user profile allows determining the code giver and code taker when two codes are similar by comparing the codes´ styles with the style of the programmers. Also if a code is copied from the internet or developed by a third party, then the style of who claims the ownership of the code is normally less proficient in coding than the third party and can be detected. The difference between the style levels is done through the style level checker module in the proposed framework. The proposed framework has been implemented and tested and the results are compared to Moss which shows comparable performance in detecting plagiarized codes.