Automated detection of source code plagiarism

Jcomp is a web-service that finds pairs of similar programs among a given set of programs. It has successfully been used in practice for detecting plagiarisms among student Java program submissions. We describe Jcomp's architecture and its comparison algorithm, which is based on Comparison code algorithm. Then, the contribution of this research is threefold: First, an evaluation of Jcomp's performance on several rather different sets of Java programs shows that Jcomp is very hard to deceive. More than 90 percent of the 77 plagiarisms within our various benchmark program sets are reliably detected, and a majority of the others at least raise suspicion. Second, a parameter study shows that the approach is fairly robust with respect to its configuration parameters. Third, we study the kinds of attempts used for disguising plagiarisms, their frequency, and their success.