APPS 2021 is the 3rd International Workshop on Adaptive and Personalized Privacy and Security which will be held ONLINE from Utrecht, the Netherlands in conjunction with ACM UMAP 2021 - User Modelling, Adaptation and Personalization, June 21-25, 2021.

APPS 2021 aims to bring together researchers and practitioners working on diverse topics related to understanding and improving the usability of privacy and security software and systems, by applying user modeling, adaptation and personalization principles.

Our special focus in 2021 will be on challenges and opportunities related to the Covid-19 outbreak for ensuring privacy and security of users' interactions in online systems (like challenges for online distance learning, e-Government, e-Commerce, the need for touchless authentication, etc.).

The workshop will address the following objectives:

• increase our understanding and knowledge on supporting usable privacy and security interaction design through novel user modeling mechanisms and adaptive user interfaces;
• discuss methods and techniques for understanding user attitudes and perceptions towards privacy and security issues in various application areas;
• identify human-centered models for the design, development and evaluation of adaptive and personalized privacy and security systems;
• discuss methods for evaluating the impact and added value of adaptation and personalization in privacy and security systems.