Security of e-voting systems does not only depend on the voting protocol 1 or the software used but concerns the whole system with all its components. To guarantee security a holistic approach, which considers all parts of such a complex system, has to be chosen. The security of an election system cannot be ensured unless every single element and its securityrelated characteristics, interfaces to other elements, and their impact on the whole system are examined. This paper presents the E-Voting System Security Optimization method, which is based on such an approach and was developed to evaluate the security of e-voting systems. This method points out security flaws, shows security optimization potential, and can be used to compare different election systems. The methodology differs from other approaches insofar as it uses a holistic approach, visualizes the security situation of an e-voting system in a clear way, and shows its potential for improvement.