The research on security issues is getting more important, as the number of embedded and networked computing systems is increasing constantly. Due to strict restrictions and requirements, only special software is used in security-critical and embedded systems. Therefore, it is also necessary to secure those software applications with a special hardware implementation of a secure processor architecture against vulnerabilities and attacks. The main idea of this book was to develop a processor core extension that provides an improved capability against software vulnerabilities and improves the security of target systems passively. This architecture can directly execute bound checking for every data access. Processor registers were added, which contain the lowest and highest value, a particular register is allowed to hold. Therefore, checks can be executed directly in hardware without performance loss, whereas checking in software would make any application intolerably slow. Based on new concepts of intermediate languages, which support data-type information within meta data at the intermediate language level, the changes would be restricted to the last step in the compilation process.