1. Information systems and security: models that stand the test of time

1.1 What is a hybrid information system?

In concrete terms, the notion of hybrid IS is a set of intermediate topologies between, on the one hand, the "traditional" IS where all IT resources are hosted and controlled directly by the entity, and, on the other hand, the IS where hosting and processing are totally deported to the cloud and IT resources managed by the entity are very reduced (for example, the simple delivery of terminal equipment to users).

The choice of topologies depends on the entity's strategy, the constraints weighing on its ecosystem and numerous criteria, including :

• entity size. Only 26% of French companies are large corporations