Abstract. We instantiate an Isabelle/HOL framework for proof carrying code to Jinja bytecode, a downsized variant of Java bytecode featuring objects, inheritance, method calls and exceptions. Bytecode annotated in a first order expression language can be certified not to produce arithmetic overflows. For this purpose we use a generic verification condition generator, which we have proven correct and relatively complete. 1 Proof Carrying Code In mobile code applications, e.g. applets, grid computing, dynamic drivers, or ubiquitous computing, safety is a primary concern. Proof carrying code (PCC) aims at certifying that low level code adheres to some safety policy, such as type safety [6], bounded array accesses [13], or limited memory consumption [4]. When such properties are checked statically sandbox mechanisms and error recovery become obsolete. In classical PCC a verification condition generator (VCG) reduces annotated machine code to proof obligations that guarantee safety. Pr...