There is a tendency in information security education at universities to not only teach protection measures but also attack techniques. Increasingly more universities offer hands-on labs, where students can experience both the attackers' and the administrators' view. Getting to know the attackers' view is thought to lead to a better understanding of information security and its problems compared to teaching only strategies for defense. The paper analyzes the situation of information security education at German and international universities. We present a method to measure knowledge in information security and - using this method in an empirical study - evaluate the offensive teaching approach. Analysis of the empirical data gathered in the study shows a tendency in favor of the offensive approach compared to the classic defensive security education.