Download our factsheet "epSOS - Technical Aspects"! To access other epSOS documents and print materials, please visit the Download Area.

Core Elements

The “Core” is part of the in epSOS defined Common Components and belongs to the business layer in the NCP architecture.
It consists of the following components:

  • WorkflowManager
  • SecurityManager
  • TransformationManager
  • TerminologyServiceAccessManager
  • AuditTrailWriter
  • AuditRepository
  • RoutingManager


The WorkflowManager is contacted by the InboundProtocolTerminator as well as the NationalConnector. This component substantiates the Process Manager pattern. It is the entry point into the business layer of the NCP. Therefore, this component is the first to be called after a message is received and deserialized. The WorkflowManager operates as an orchestrator and undertakes the chain of operation calls. The operations are exposed by interfaces of other business layer components and, ultimately, the result will be conveyed to the OutboundProtocolTerminator or to the National Connector.


The SecurityManager is necessary for certificate validation and XML-Signature creation and validation. It is mandatory that a list of all trusted certificates are available to the SecurityManager in order to check whether the given certificate is a member of the Circle of Trust. The certificate validation includes a mathematical check, a validity check and the OCSP call.


The WorkflowManager will apply this component in the following two scenarios: for data transformation from a national language to the epSOS Reference Terminology or for data transformation from the epSOS Reference Terminology to a national language.


This component is applied by the TransformationManager. It is responsible for translating a given concept designation into the requested target language as well as transcoding a given “local” coded concept into the appropriate epSOS coded concept. This is achieved by using the information defined by the Terminology Repository. The Terminology Repository is a database that is part of the NCP and represents the epSOS Reference Terminology. The content of the Terminology Repository is specific for each PN. It is the responsibility of the PN to maintain and update the content of the Terminology Repository.


Every transaction in epSOS must be audited using a limited amount of information. National requirements for an extended audit must be undertaken in the NationalConnector or the national infrastructure. The AuditTrailWriter component is responsible for formatting an EventLog message compatible with the Audit Trail and Node Authentication and  transmitting it securely to the AuditRepository.


This component is responsible for storing an audit trail that is captured by the AuditTrailWriter component. Additionally, this component exposes an interface that is used by the national infrastructure to selectively query fragments of the audit trail. The content of the AuditRepository will be analyzed in the national infrastructure. Therefore, the AuditService interface has a broad general structure that can be adjusted by the Participating Nations according to their specific needs.


Before any message can be sent by the NCP (country B), information for the correct routing to the corresponding NCP (country A) must be resolved. The outcome of the RoutingManager is a URL of the corresponding NCP.

The address lookup table is a XML-document that can be stored in the NCP's local file system or be fetched (and cached) from a central URL.