In principle all master courses offered at the TU/e can be chosen as free electives. We do recommend to take more than the required minimum number of courses from the above lists. Other mathematics and computer science related courses from the TU/e and RU are also recommended, as well as security-related courses from other universities (provided their topics do not overlap with the TU/e and RU courses you already take).
Your complete study program including the free electives always requires approval by the examinations committee. Your mentor will help you to compose a balanced program that is very likely to be approved.
Some courses may be prescribed as homologation courses (up to 15 credits) to make up for deficiencies in former education. This prescription is part of the admission decision.
If you do not (yet) have a degree from another country or at least 15 credit points in international experience you should reserve 15 credits from the room for free electives to take courses abroad or to do an internship of 15 credits abroad.