SafeTSA is an SSA-based intermediate representation for mobile code, that has been developed as an alternative to Java's Bytecode, over which it has several advantages: 1. SafeTSA is better suited as input to optimizing dynamic code generators and allows a wide range of optimizations to be performed at the code producer. 2. SafeTSA provides incorruptible referential integrity and uses „type separation“ to achieve intrinsic type safety. These properties reduce the code verification effort at the code consumer considerably. 3. SafeTSA can transport the results of null- and bounds-check elimination in a tamper-proof manner. In the presentation we will show which kind of extensions are necessary for transforming ordinary SSA-form into a convenient mobile code format. Particularly, techniques that are used for the construction of type safeness and referential integrity as well as memory safety will be discussed extensively. Furthermore, we will shortly address how type extensions can be used for safe program annotations that could be utilized by a JIT compiler for code optimization on the consumer side of a mobile code system. In the second part practical evaluations of the SafeTSA format will be discussed using performance results that have been measured for SafeTSA programs with various optimizations on both the IA32 and PowerPC architecture.