The Electronic Product Code (EPC) is the basis to identify product on instance level. In combination with Radio Frequency Identification (RFID) it enables wireless tracking and tracing of individual products throughout the product's lifecycle in the supply chain. Once a product passes a reading gate associated meta data is stored in distributed event repositories (EPCIS). For example, event data consist of the product's unique identifier, date and time, reading location, and involved business steps. Analysis of the product's event data is the basis for authenticity checks to prevent product counterfeits. However, the semantic combination of event data can be misused, e.g. to retrieve active product ingredients, to fake contents of packages, or to derive business relationships between business partners. The designed security extensions for EPCglobal networks address the control of access to event data, the secured exchange of event data, and its filtering by incorporating in-memory technology for the first time. They perform real-time analyses of the complete access history of every participant to derive individual access rights and to restrict access to event data even after their exposure. In contrast to traditional access control mechanisms that enable a bivalent control of access (access granted vs. access denied) the developed security extensions enable a continuous spectrum of access while filtering sensitive data from the result set. Feasibility of the security extensions are proofed by integrating them into the open-source event repository FOSSTRAK EPCIS.