https://confluence.simplprogramme.eu/display/SIMPL/Annex+6+-+Architecture+building+blocks Related to the security capabilities, the functions gathered by Access control & Trust capability will be constantly required whenever any participant (consumer, provider or governance authority) accesses Simpl-Open. Mapping end user roles with participant attributes (Role-Based Access Control - RBAC & Attribute-Based Access Control - ABAC), as well as authorizations to proceed with an action are addressed here. In this sense, every relation of the user with a data layer building block or infrastructure provisioning is closely screened by the Access Control & Trust. Simpl-Open will provide identification, authentication and authorization (IAA) building block for communication between data space participants, and integrate existing IAA systems of participating organisations for IAA of users within the organisation. To ensure that all usage policies are effectively enforced within the data spaces, Simpl-Open provides a policy enforcement capability. It also provides the necessary capabilities to submit/review/approve onboarding requests and deliver to the applicant the necessary security credentials to join a data space.