On March 6, 2025, the INTER.SECT partners held an internal methods workshop on data linkage and geomasking at the TMF premises. The aim of the workshop was to clarify the details of the data linkage strategy in INTER.SECT and to solve related legal, organisational and methodological questions. Prof. Dr. Rainer Schnell from the University of Duisburg-Essen supported the one-day event with his extensive expertise in the areas of data linkage and geomasking.

In addition to contributions from the INTER.SECT partners on the legal framework conditions for use and the structure of routine, authority, primary and geodata, Professor Schnell provided a comprehensive overview of methods in the areas of data linkage and geomasking. These presentations were followed by a working phase in which the details of a possible data linkage strategy in INTER.SECT were further elaborated.

The main results of the workshop are:

• The data linkage is expected to take place in BAMF.
• A privacy-preserving record linkage is very error-prone and should therefore be avoided if possible. Instead, direct linkage may be possible, provided that the necessary technical and organisational measures are put in place.
• The legal basis for data linkage requires further clarification.