Master-Thesis

The aim of this thesis is the design and the implementation of an application which allows the user to establish secure connections on mobile phones. This includes a framework for encrypted phone-calls. In the design-phase the cryptographic primitives useful for the task of secure mobile communication have to be selected and a choice for the key infrastructure has to be made. An important aspect here is the usability of the resulting product: For example it is necessary that a necessary key agreement between two parties is as cheap as possible (in terms of money) but establishes still a reasonable amount of security. The implementation-phase is mainly concerned with Sun's J2ME-framework, which enables the developer to write applications for mobile phones which are (in theory) portable to every JAVA-capable mobile phone.