Secure code distribution

The Java Virtual Machine does not offer a way for code obtained from trusted sources to be granted extra rights. The article describes two approaches to authentification for code distribution: one extends the JVM to include a digital signature in applets; the other uses MIME encapsulation to take advantage of available security infrastructures. The signed-applet approach gives a programmer more flexibility because it addresses the security issues at a more fundamental level. However, signed-applet security mechanisms may vary for different code distribution schemes, making integration difficult. The MIME-based approach provides a unified security interface. It is more efficient in the sense that all classes can be encapsulated in one multipart attachment, and a single signature or verification operation will cover all classes. The approaches can also be combined and tailored to satisfy various requirements. Ultimately, operating systems must support the concept of a secure compartment so that separate resource management policies can be implemented for the secure compartment and the rest of the system.