Users of technology encounter various IT security mechanisms in their everyday lives. If these mechanisms fail to support everyday activities, they either get in the way, or the users find a way to work around them. Even though users manage to carry out everyday activities by using substandard IT security mechanisms or via workarounds, it will influence their experience of security. If researchers and designers only focus on IT security artifacts and fail to take the user experience into account, incorrect processes or workarounds will occur. Accordingly, to get users to follow the correct process may seem to be a criterion of success, even though it may yield a less appropriate experience of security. This dissertation deals with an improved understanding of IT security sensitive IT artifacts and presents three design methods, and a framework for addressing the complexities and contingencies of security experiences in design. The methods: Mobile probing, Prompted exploration workshops, and Acting out security involve potential future users in the process of designing IT security sensitive IT artifacts. Mobile probing collects narratives of user encounters with IT security. Prompted exploration workshops present the users with seven themes and involve them in the design of IT security sensitive IT artifacts. Acting out security lets users try out prototypes in situations where security handling is infrequent and quick. All three methods have been developed and deployed as an integral part of a research through design process. An everyday mobile digital signature solution has been designed, and the design problem, the design process, and the design results are presented in this dissertation. Several of my empirical findings show that the way users experience security does matter. Users’ experiences of security influence the way they make sense of, assess, and handle IT security mechanisms. Moreover, I studied cases in which the users handled IT security sensitive technology in a secure way, but still had unwanted experiences of security. Through the developed design methods I was able to activate and access study participants’ prior experiences of making sense of IT security sensitive technology. Moreover, the methods helped clarify users’ immediate experience in an encounter with IT security sensitive technology. The findings were integrated into the design of a digital signature solution, and in this process I developed a framework for structuring empirical findings for the design of IT security sensitive IT artifacts.