The ADA Data Access (ADA) project is dedicated to researching secure, decentralized data storage for resource-limited devices. The paradigm of self-sovereign identity (SSI) can be applied in many different technology and life domains. A large part of current SSI research focuses on (sovereign) identities for natural and legal persons. However, SSI principles can also be applied to more abstract entities such as devices, objects, or software.In the ADA Data Access project, an architecture is being designed that enables the application of SSI in the IoT domain. To this end, a data storage architecture is being developed that can be used as a decentralized verifiable data registry (VDR). This VDR allows the creation, storage, and retrieval of DID documents that form the basis for SSI use cases. In the course of the project, the requirements of IoT applications for SSI will be defined. Based on this criterion catalog, an architecture will be designed that will then be implemented in a demonstration setup.ADA is being funded as a micro-project under the Software Campus program with funds from the BMBF.