There might be some people that know of this info of a decrypter named Mr. Lee. But the people who don't know of this, might want to consider looking toward the site below, if their interested in the kof'2000 and Metal Slug 3.
http://www.jvrba.com/showthread.php?threadid=1241
http://www.jvrba.com/showthread.php?threadid=1241