The 6th IEEE International Conference on intelligent data and security (IEEE IDS 2021) is a research event cooperated with a number of conferences, such as IEEE BigDataSecurity 2021 and IEEE HPSC 2021. This conference provides engineers and scientists in computing domain with an academic forum in which the new research achievements, ideas, and results are shared. The state-of-the-art smart computing applications and experiences in cloud computing and smart computing will be represented in this academic event. IEEE IDS 2021 is the next edition of a series of successful academic events, including IDS 2016 (New York, USA), IDS 2017 (Beijing, China), IDS 2018 (Omaha, USA), IDS 2019 (Washington DC, USA), and IEEE IDS 2020 (Baltimore, USA).