||Software itself and the contexts, it is used in, typically evolve over time. Analyzing and ensuring security of evolving software systems in contexts, that are also evolving, poses many difficulties. In my thesis I declared a number of goals and propose processes for the elicitation of attacks, their prerequisites and mitigating security patterns for a given architecture model and for annotation of it with security-relevant information. I showed how this information can be used to analyze the systems security, in regards of modeled attacks, using an attack validity algorithm I specify. Process and algorithm are used in a case study on CoCoME in order to show the applicability of each of them and to analyze the fulfillment of the previously stated goals. Security catalog meta-models and instances of catalogs containing a number of elements have been provided.