Functional Model. The vision of the 4SECURail CHIRP4Rail concept, as previously presented in section 8.1, is an implementation as a “virtual” and horizontal model, spread across several IM/RU organisations at the EU level with the aim to connect them and support cybersecurity information sharing and actionable intelligence dissemination. This means the proposed model does not aim to implement the local/national nor corporate CSIRT operations (already established); instead it aims to support collaborative threat intelligence and information sharing among the key railway cybersecurity organisations and stakeholders at the European level, also engaging with the National Authorised CERTs/CSIRTs and external threat intelligence providers. Figure 7 below shows an overview of the 4SECURail functional model vision:
Functional Model. Layers, Workflows, Functional Entities As in the case of the OAIS model, the function view of the PoF Reference Model, or the functional model for short, considers the main functional entities of the proposed reference model. Furthermore, we also describe the main workflows in the model and how the functional entities contribute to those workflows. Again the stress is on the parts, which connect the two types of systems, Active System and DPS, with each other. The proposed PoF Functional Model is made up of three layers, namely the Core Layer, the Remember & Forget Layer and the Evolution Layer: the Core Layer considers the basic functionalities required for connecting the Active System and the DPS; building upon this layer, the Remember & Forget Layer introduces the brain-inspired and forgetful aspects into the PoF Reference Model implementing more advanced functionalities for the preservation preparation and the re-activation workflow; finally, the Evolution Layer, is responsible for all types of functionalities dealing with long-term change and evolution such as implementing the idea of contextualized remembering. The different workflows and functional entities in the PoF Functional Model are associated to the three model layers above, as summarized in Table 1 and depicted in Figure 2. The description of the layers, workflows and functional entities is provided in the next Sections. An overview of the PoF Functional Model components (layers, workflows, functional enti- ties) is depicted in Figure 2): within each layer box the relevant entities and workflows are shown. In the following Sections we provide a more detailed representation of each work- flow, with the steps associated to each process and the involved entities. It is worth noting that Figure 2 already makes some assumptions about the functionalities implemented in the Active System and, especially, the DPS: those functionalities, which are parts of one of the respective systems, are not explicitly listed in the PoF Reference Model. For our purpose, we assume a OAIS compliant DPS implementing functionalities such as Ingest, Data Management, Preservation Planning, Archival Storage and Access of preserved content (see [CCSDS, 2012]). The three layers are used in the following to describe the functional view of the PoF Reference Model in more detail.
Functional Model. The Functional Model of the PoF Framework is concerned with the main workflows of the preservation approach introduced by ForgetIT and the functionalities required for realizing those workflows. Special focus is given to the novel concepts introduced, namely the as- pect of using Managed Forgetting in support of preservation, the role of contextualization and the impact of evolution. The Functional Model is complemented by the Information model presented in the next section. As in the case of the OAIS model, the function view of the PoF Reference Model, or the functional model for short, considers the main functional entities of the proposed reference model. Furthermore, we also describe the main workflows in the model and how the functional entities contribute to those workflows. Again the stress is on the parts which connect the two types of systems, Active System and DPS, with each other.
Functional Model
