This paper presents an innovative solution to manage security and trustiness in Osmotic Computing. Osmotic Computing dynamically manages Cloud, Edge and IoT resources across federated environments set up by different and cooperating stakeholders. In this context, the Software Defined Membrane (SDMem) is the main component responsible to orchestrate the osmotic transfer of microelements (MELs) across different environments straightening the security needs of such a complex ecosystem. The basic idea presented in this paper is to leverage Private Blockchain technologies in SDMem implementation over federated systems. Data access activities will be logged in a private distributed Blockchain-based ledger. This will allow to have a certified, non-repudiable record of all the data accessed performed by distributed computing, thus assuring the overall ownership and integrity of data and processes …