IEEE BigDataSecurity 2021 is the next event after a series of successful academic get-togethers, including BigDataSecurity 2020 (Baltimore, USA), BigDataSecurity 2019 (Washington, DC, USA), BigDataSecurity 2018 (Omaha, NE, USA), BigDataSecurity 2017 (New York, USA), BigDataSecurity 2016 (Beijing, China), and BigDataSecurity 2015 (New York, USA).