"Hard X-ray observations provide a direct observational link to the acceleration and transport of highly energetic particles in solar flares, a phenomenon that has many significant solar-terrestrial consequences. We propose to mainstream the exploitation of high energy solar physics data in Europe. To achieve this overall objective, we will proceed with three complementary activities: theory, computation, and technology. The theory activity will build the background necessary to generalize the use of these data. The computation activity will focus on mathematical techniques to efficiently extract information out of the data. The technology activity will build up on these two work packages to generate science ready data products. These products will be easy to use by both the broader solar and heliospheric physics community, and the space weather community. More specifically, these communities will be able to use these data to build flare prediction models and to integrate them to test their own data analysis projects. The three activities will pave the way not only for the exploitation of the sheer amount of data already available today, but also for the future high energy solar space missions planned. This way, the project as a whole will guarantee a stable and long term positioning of Europe in the sustainable exploitation of such data products."