Java bytecode verification with dynamic structures

Java applets run on a Virtual Machine that checks code’s integrity and correctness before execution using a module called Bytecode Verifier. Java Card technology allows Java applets to run on smart cards. Large memory space requirements of the verification process do not allow the implementation of a Bytecode Verifier embedded in the Java Card Virtual Machine. To address this feasibility problem, we propose a modified verification algorithm that optimizes the use of system memory. The algorithm, inspired to compilers’ techniques, partitions the code of the methods into control regions. In this way data structures can be dynamically allocated and the verification process can be applied locally to a subset of instructions.