Most (if not all) of advanced courses in computer security are hosted by the Graduate School of Information Security, KAIST. Most of these courses can be taken by KAIST CS undergraduate. Feel free to contact the instructors if you are interested in knowing more about the advanced topics!
Cryptography
IS581: Security Proof and Attacks in Cryptography
Software Security
System Security
IS631: Kernel System Security
Network & Web Security
IS539: Network Security
IS542: Web Service Security and Privacy