Improved sandboxing for java virtual machine using hybrid execution model

Safe program execution environment using sandboxing mechanism is one of important differences of Java¹ programming language and traditional languages. This safety characteristic can be preserved when a program is written in pure Java language, but it may be lost when machine-dependent native code is used in the program. We address this problem by incorporating a novel VM structure that improves the reliability and security of sandboxing mechanism of Java VM. It uses a hybrid execution model combining interpreted execution of Java code and emulated execution of native code. Unmodified native JNI methods are executed by using an emulation engine using binary translation with additional sandboxed execution enforcement. Experimental results of prototype implementation show that performance penalty for SPECjvm98 benchmarks is relatively small, ranging from 0% to 30% meaning that the proposed approach is promising.