Agent Oriented Software Engineering and security patterns have been proposed as suitable paradigms for the development of secure information systems. However, so far, the proposed solutions are focused on one of these paradigms. In this paper we propose an agent oriented security pattern language and we discuss how it can be used together with
the Tropos methodology to develop secure information systems. We also present a formalisation of our pattern language using Formal Tropos. This allows us to gain a deeper understanding of the patterns and their relationships, and thus to assess the completeness of the language
