What Is the technology Used By CODECHEF to Catch cheaters and people who copy paste the code?
its MOSS and codechef uses it …
Codechef uses MOSS (Measure Of Software Similarity) for plagiarism detection which is an automatic system for determining the similarity of programs.
You can find about MOSS here: http://theory.stanford.edu/~aiken/moss/
And to know how it works just download this PDF
Codechef uses moss to detect plagiarism.
Read in deatil here - https://theory.stanford.edu/~aiken/moss/