Today's live training environment is comprised of many systems in various states of configurations with a limited ability to leverage shared services. The future of live training systems will evolve to a Training as a Service (TaaS) state to reduce overall operating costs, implement new technologies to improve the training experience, and centrally manage the training exercise of distributed training systems. With a TaaS approach to system architecture, a number of new cybersecurity and DoD Information Assurance requirements will need to be implemented in order to ensure the Confidentiality, Integrity, and Availability of DoD information Systems. Previous papers (Lanman and Linos, 2012) have outlined in greater detail the motivation and migration strategy for a pilot study on implementing TaaS within the Common Training Instrumentation Architecture (CTIA) used by the Army's Live Training Transformation (LT2) Product Line. This paper will present a number of cybersecurity threats, challenges, requirements, and commercial best practices for secure operations as well as Certification and Accreditation (C&A) requirements of a TaaS approach. Threats not previously present in isolated system architectures will now need to be countered with appropriate defense mechanisms across physical and logical boundaries. This paper will describe and discuss cloud computing guidance for cybersecurity from the U.S. Army Chief Information Officer/G-6 guidance, National Institute of Standards and Technology (NIST), and the Defense Information Systems Agency (DISA). This paper will present a strategy for implementing commercial best practices to facilitate secure operations of a cloud computing approach to live training. Finally, the purpose of this paper is to provide an overview of the security requirements associated with cloud computing, document the certification process necessary to achieve an Authorization To Operate (ATO) for a cloud implementation, and discuss unique best practices associated with a PM TRADE implementation of a TaaS architecture.