  The 2nd International Workshop on Adaptive Cyber Defense was held at the
Florida Institute of Technology, Florida. This workshop was organized to share
research that explores unique applications of Artificial Intelligence (AI) and
Machine Learning (ML) as foundational capabilities for the pursuit of adaptive
cyber defense. The cyber domain cannot currently be reliably and effectively
defended without extensive reliance on human experts. Skilled cyber defenders
are in short supply and often cannot respond fast enough to cyber threats.
  Building on recent advances in AI and ML the Cyber defense research community
has been motivated to develop new dynamic and sustainable defenses through the
adoption of AI and ML techniques to cyber settings. Bridging critical gaps
between AI and Cyber researchers and practitioners can accelerate efforts to
create semi-autonomous cyber defenses that can learn to recognize and respond
to cyber attacks or discover and mitigate weaknesses in cooperation with other
cyber operation systems and human experts. Furthermore, these defenses are
expected to be adaptive and able to evolve over time to thwart changes in
attacker behavior, changes in the system health and readiness, and natural
shifts in user behavior over time.
  The workshop was comprised of invited keynote talks, technical presentations
and a panel discussion about how AI/ML can enable autonomous mitigation of
current and future cyber attacks. Workshop submissions were peer reviewed by a
panel of domain experts with a proceedings consisting of six technical articles
exploring challenging problems of critical importance to national and global
security. Participation in this workshop offered new opportunities to stimulate
research and innovation in the emerging domain of adaptive and autonomous cyber
defense.
