Requirements engineering has attained an important role in software development over the last few years as developers and other stakeholders have realized the importance of adequate requirement analysis and design in software development processes. However, the specification and analysis of functional requirements is better established compared to non-functional requirements. This could be attributed to the fact that nonfunctional requirements, such as reliability, accuracy, performance, usability and security are often subjective.

Security requirements are often incorporated in an ad hoc manner or considered at post-requirement phase. It is believed that addressing these requirements during the early phase of system development will improve the quality of developed applications. Confidentiality is an aspect of a system?s security requirements aimed at preventing unauthorized use of personal or corporate data. Concerns from the different stakeholders, which can be diverging, have to be addressed in realizing confidentiality requirements. These concerns are also usually influenced by proposed system functions. This research is aimed at precisely defining confidentiality requirements and applying this for modelling and reasoning in confidentiality requirements engineering.