Protection of European borders and Seas through the Intelligent Use of Surveillance (PERSEUS) is an FP7 demonstration project supported by the FP7 Security Research theme under DG-Enterprise. Its purpose is to build and demonstrate an EU maritime surveillance system integrating existing national and communitarian installations and enhancing them with innovative technologies. When connecting together surveillance systems of two or more organizations, the trust for others and their cyber security is the main issue. Security audit is a way to demonstrate an organization’s security level. This multiple case study analysis consists of six individual case studies that research how the Finnish national security auditing criteria KATAKRI is suitable for different types of organizations when they are developing their security levels. The cross-case conclusions investigate, how KATAKRI could be applied when developing information security policies of different organizations in the perspective of information sharing. The results revealed that KATAKRI is a useful tool for developing organizations’ security policies. However, KATAKRI should be redeveloped towards a tool that encourages and simplifies information sharing instead of being a burden.