Together with
Gordon Plotkin he noted the connection between
existential types and
abstract data types. Mitchell's early computer science research focused on programming analysis and design, where he played a pivotal role in developing type theory as a foundation for programming languages, a view that is now dominant in the field. For the past 15 years, his research has focused on computer security, developing analysis methods and improving network protocol security, authorization and access control, web security, and privacy. Mitchell has been at the forefront of Web and network security research and education for more than a decade and has helped train thousands of students in programming languages and hundreds of expert-level professionals in the area of cyber-security. His efforts have resulted in the development of concepts used in the popular Java programming language, improved the security of widely used wireless networking protocols, contributed to the security architecture of the Chrome browser and other components of the modern web. In August 2012, Mitchell was appointed by Stanford President
John L. Hennessy as the Vice
Provost for Online Learning, a newly created position responsible for overseeing Stanford's online learning initiatives. ==References==