Current research of the Norwegian samfunnssikkerhet concept appears to be lacking, with few scientific publications advancing the understanding of the concept. This weakness is addressed through the paper's empirical exploration of challenges in the work on samfunnssikkerhet (Paper aim #1), where the resulting insight informs an epistemological understanding of the concept of samfunnssikkerhet (Paper aim #2). The paper identifies four challenges in the work on samfunnssikkerhet, which suggest that samfunnssikkerhet is about mobilizing against both known and unknown threats through broad and border-crossing cooperation and about flexible methods and design approaches. It is concluded that the paper's empirical exploration of the samfunnssikkerhet concept contributes to a clarification and overall empirical revitalization of the concept. A recommendation to safety and security researchers is to further develop the empirical understanding of the samfunnssikkerhet concept, including through validation of the challenges identified in this paper and continuous mapping of additional and future challenges. This can give the samfunnssikkerhet concept, including its relation to concepts such as resilience, risk and societal security, a clearer meaning and consequently a stronger unifying role in efforts to prevent and manage today's dynamic threats both within and outside Norway.