InfiniBand is an input/output interconnect technology for high performance computing clusters – it is employed in more than one-quarter of the world’s 500 fastest computer systems. Although InfiniBand was created to provide extremely low network latency with high quality of service, the cyber security aspects of InfiniBand have yet to be investigated thoroughly. The InfiniBand architecture was designed as a data center technology that is logically separated from the Internet, so defensive mechanisms such as packet encryption were not implemented. The security community does not appear to have taken an interest in InfiniBand, but this is likely to change as attackers branch out from traditional computing devices. This chapter discusses the security implications of InfiniBand features and presents a technical cyber vulnerability assessment.