After spending one year in the United States as a foreign exchange student at Brandeis University in Boston, he finished his diploma in Mathematics in Regensburg in 1986.

He received his doctorate of natural sciences with dissertation Vektorbündel und der Satz von Cayley-Bacharach from University of Regensburg in 1989, working under advisor Ernst Kunz.

[1] Next came a post-doctoral fellowship at Queen's University in Kingston, Ontario, Canada, from 1989 to 1991, working in algebraic geometry with Professor Anthony Geramita.

He gained the title of International Correspondence Chess Grandmaster[2] (GMC) 1994, from his result in the 1988–95 Von Massow Memorial tournament.

Kreuzer played board six in the finals, on the German team which shared the gold medal at the 11th Correspondence Chess Olympiad, 1992–1999.