The European Network and Information Security Agency (ENISA) issued two new reports related to two formal structures of collaboration among stakeholders: Cooperative Models for Public Private Partnership (PPP) and Information Sharing and Analysis Centres (ISACs). The reports are based on collected information on best practices and common approaches. The study on PPP identifies four models that exist within the EU: institutional, goal-oriented, service outsourcing, and hybrid. It also underlines the importance of a legal basis for creating PPPs, private-private and public-public collaboration, open communication and a pragmatic approach, and participation of small and medium sized enterprises (SMEs). The other study categorises ISACs -trusted entities fostering the sharing of information and good practices about physical and cyber threats and mitigation -into three models: country focused, sector specific and international structures; it emphasises the importance of motivating the private sector, establishing a facilitator for the involvement of participants, production of valuable results by ISAC, and cross-sector collaboration. Both reports underline that trust is the most essential factor in co-operation across sectors.