Software security is an emerging area in software development. More and more vulnerabilities are published and highlight the endangerment of systems. Hence, software designers and programmers are increasingly faced with the need to apply security solutions to software systems. Security patterns are best practices to handle recurring security problems. The abundance of documented security patterns calls for meaningful classifications to ease searching and assessing the right pattern for a security problem at hand. Existing classifications for security patterns consider only a small number of patterns and their purpose is often focused on implementation issues.