The previous chapters of this book have presented promising approaches in the secure software engineering ?eld. However, the ?eld is still in its infancy and a number of challenges still need to be answered. The main aim of this chapter is to list and discuss nine challenges that we ?nd important for the advance of the secure software engineering ?eld. The main idea behind each challenge is presented in a short sentence followed by a discussion, which indicates why the challenge is important. In some cases, the discussion provides some ideas of how the challenge could be met.