In this chapter, we have discussed our experiences in using aspect-oriented programming to develop security components for distributed applications. We believe that we have illustrated the effectiveness of AOP technology with two application-level security problems, which resulted in examples that are beyond toy-level demonstrations of the technology at hand. In the long run, however, it is clear that support at the level of development processes and environments will be essential for aspect-based technology to become widespread.
We believe that security greatly benefits from enhanced modularization with aspects. The key advantages in this context are the full separation of business and security logic, which allows security experts to concentrate on their core business, and the centralization of the security policy that raises policy verification to a higher level. A recent doctoral thesis  discusses the feasibility, merits, and drawbacks of using aspect-oriented software development for application-level security in more detail.
Finally, it is also fair to state that by only focusing on security, we have not covered the challenge of combining aspects that result from complementary, relatively unrelated concerns. The use of the technology in such a context, where advanced aspect compositions is clearly required, is the focus of ongoing and future work.