It is our great pleasure to welcome you to the eleventh edition of the ACM Conference on Data and Application Security and Privacy (CODASPY 2021), which follows the successful tenth edition held online in August 2020 due to the pandemic. This conference series has been founded to foster novel and exciting research in the data and application security and privacy arena and to help generate new directions for further research and development. The initial concept was established by the two cofounders, Elisa Bertino and Ravi Sandhu, and sharpened by subsequent discussions with several fellow data security and privacy researchers. Their enthusiastic encouragement persuaded the co-founders to move ahead with the always daunting task of creating a high-quality conference. Data and applications that manipulate data are crucial assets in today's information age. With the increasing drive towards availability of data and services anytime and anywhere, security and privacy risks have increased. Vast amounts of privacy-sensitive data are being collected today by organizations for a variety of reasons. Unauthorized disclosure, modification, usage, or denial of access to these data and corresponding services may result in high human and financial costs. Important applications such as homeland security, social networking and social computing provide value by aggregating input from numerous individual users, and the mobile devices they carry. The emerging areas of Cloud Computing and Internet of Things also pose serious privacy and security challenges. To achieve efficiency and effectiveness in traditional domains such as healthcare, there is a drive to make these records electronic and highly available. The need for organizations to share information effectively is underscored by rapid innovations in the business world that require close collaboration across traditional boundaries. Security and privacy in these and other arenas can be meaningfully achieved only in context of the a