This document provides a clear description of the COLLABS level-2 security components. In particular, it describes fine-grained authorization for constrained environments, relying on distributed ledger technologies for exchanges between different involved mechanisms. We show how COLLABS ledger-based security modules can secure inter-device communications and enhance the trust level in inter- The project COLLABS has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 871518. device collaboration, on several aspects of the Smart Factory lifecycle. We describe how COLLABS ensures that all the data collected from connected objects, and all the actions are authorized following an effective security policy. This document also illustrates the main data flows with sequence diagrams, describing and visualizing processes involving each component, as well as mapping of COLLABS level-2 security components to the use case scenarios.