Tamper-proofing basis path by using oblivious hashing on Java

Java programs are often downloaded (distributed) to unknown environments, so protect Java code from malicious modification is an important issue. This paper presents a tamper-proofing software technology on basis paths for stack-machine based languages, such as Java, by improving Oblivious Hashing. Our approach is based on a new dynamic stack-tracing approach which inserts hash instructions to monitor the top of the stack to check whether the program running has been tampered with or not. A user can choose one or more methods in a class to tamper-proof program. The protective codes are added to basic blocks at the bytecode level. We developed a new approach to protect constants and variables by alternative hashing functions. The overhead is proportional to the number of Load and Push instructions to be protected.