Given such signatures for a pair of works, you can simply compute a score using a "similarity" metric, which tells how close these two works are (as given by their signatures). This score is low if both works are of the same author, but high if the authors are different.
Once you can compute the similarity metric, do some research using known works by the same author and known works of other authors. What values of the score are "low enough" to indicate that the author is the same? Pick an appropriate threshold for the score so that your program automatically prints both the score and a message that the authors are the same whenever the score is below your threshold.