HoTSoS 2019. 6th Annual Hot Topics in the Science of Security (HoTSoS) Symposium, Nashville, Tennessee. April 1-3, 2019. Submissions due 7 January 2019. https://cps-vo.org/group/hotsos Submissions are solicited for the 6th Annual Hot Topics in the Science of Security (HoTSoS) Symposium, which will be held April 1-3, 2019 at the Wyatt Center on the Peabody Campus of Vanderbilt University in Nashville, Tennessee. Scope, Goals & Vision This symposium solicits original and solid scientific work in security and privacy which examines the scientific foundations of trustworthy systems for security and privacy, and it can be generalized across multiple domains with quantifiable evidence for advancing security objectives. The symposium program will include invited talks, refereed papers, panels, tutorials, and posters. The poster session will include a poster competition on developing security metrics. The papers will appear in the conference proceedings to be published by ACM Press. We invite submissions on any topic related to science of security that aligns with the conference scope and goals listed above. HoTSoS 2019 will highlight the following themes: * Resilient Architectures for designing and analyzing system architectures that deliver required service in the face of compromised components, * Scalability and Composability for automating the construction of provably secure systems from components with known security properties, * Policy Governed Secure Collaboration for handling data across different domains of authority while ensuring security and privacy, * Security-Metrics-Driven Development and Evaluation for guiding choice-making in security engineering and response by assuring or predicting the security properties of cyber systems, * Understanding and Accounting for Human Behavior, including modeling users, operators, and adversaries, to for enabling the design, modeling, and analysis of systems with specified security properties, * Privacy Policy Enforcement for enabling the use (i.e., collect, store, and share) of data in accordance with requirements, and * Foundations for the security of cyber-physical systems security and resilience, including applications to the Internet of Things.