Free flow of data across nations around the world will surely bring about huge benefits to humankind. But there are concerns that it can infringe on an individual’s human rights, take economic advantages away from those having more data, or can endanger national or regional security. To challenge these issues, Data Free Flow with Trust (DFFT) was proposed by the prime minister of Japan at the G20 summit meeting in 2019. It emphasizes the concept of trust in data communication. We first consider the difference between trust and security. Then we make a scientific model of DFFT where trust is defined in the context of data flow. Using this model, we list the set of core technological problems for realizing DFFT and introduce the R&D strategy of Hitachi in approaching them.