Security has become a major concern as the execution of code downloaded from the Internet gained wide acceptance. Designers of programming languages such as Java TM have addressed this issue by introducing built-in security mechanisms. Most reflective software architectures, however, have failed to do so.
We have argued that the lack of security mechanisms in reflective architectures, i.e., the lack of discipline in inter-level and inter-meta-object communication, has negative implications for the reliability and adaptability of meta-level components.
We advocate that MOPs should be designed so as to avoid direct explicit interactions between levels and to favor implicit interactions. Meta-objects should be hidden from objects and other meta-objects, so that they can retain full control over objects under their responsibility and prevent unauthorized access to them.
The MOP of Guaranį is a simple extension of the secure MOP and the reconfiguration mechanisms described in this paper, in order to support composition of meta-objects [5]. This extension does not violate the discussed security properties; on the contrary: it enriches the MOP by allowing code reuse and hierarchical control of meta-objects.
Although our current implementation of Guaranį is an extension of the Java platform, the security mechanisms we have proposed are not limited to the Java programming language, and can be adopted by MOPs based upon other programming languages. Even for languages not designed with security in mind, a secure MOP can help developing reliable, adaptable and secure reflective applications.