Background and Objective: Nowadays usage paradigms of medical imaging resources are requesting vendor-neutral archives, accessible through standard interfaces, with multi-repository support. Regional repositories shared by distinct institutions, teleradiology as a service at Cloud, teaching and research archives, are illustrative examples of this new reality. However, traditional production environments have a server archive instance per functional domain where every registered client application has access to all studies. This paper proposes an innovator ownership concept and access control mechanisms that provide a multi-repository environment and integrates well with standard protocols. Methods: A secure accounting mechanism for medical imaging repositories were designed and instantiated as an extension of a well-known open-source archive. A new Web services layer was implemented to provide a vendor-neutral solution complaint with modern DICOM-Web protocols for storage, search and retrieve of medical imaging data. Results: The concept validation was done through the integration of proposed architecture in an open-source solution. A quantitative assessment was performed for evaluating the impact of the mechanism in the usual DICOM Web operations. Conclusions: This article proposes a secure accounting architecture able to easily convert a standard medical imaging archive server in a multi-repository solution. The proposal validation was done through a set of tests that demonstrated its robustness and usage feasibility in a production environment. The proposed system offers new services, fundamental in a new era of Cloud-based operations, with acceptable temporal costs.