The paper considers the issues of providing secure interaction of open information systems based on systematic and process approaches. In particular, a set of components of the Open System Environment reference model that implements the property of interoperability (interaction of open information systems) is defined; an algorithm for selecting protection mechanisms that meet the properties of information security (confidentiality, integrity, availability) is presented; a set of protection mechanisms that provides secure interaction according to the information security properties is defined and verified against external potentially dangerous threats. The presented results are consistent with the object interoperability stack published by the Commission of the European Parliament.