How do we ensure information security for a computer that is entangled with the neural processes of a human mind - and for the human mind that is interconnected with such a device?The need to provide information security for neuroprosthetic devices grows more pressing as increasing numbers of people utilize technologies such as cochlear implants, artificial retinas, robotic prosthetic limbs, and deep brain stimulation. Moreover, more advanced neuroprosthetic technologies designed for human enhancement are expected to someday transform their users' sensory, motor, and cognitive capacities in ways so radical that their nature can best be described as "posthuman." It is essential not only to ensure the information security of such neuroprosthetic devices themselves but - more importantly - to ensure the physical and psychological health, autonomy, and personal identity of the human beings whose cognitive processes are inextricably linked with such devices. Information security practitioners must not only guard against threats to the confidentiality and integrity of data stored within a neuroprosthetic device's internal memory; they must also guard against threats to the confidentiality and integrity of thoughts, memories, and desires existing within the mind the of the device's human host.This volume is the first book dedicated to studying these issues comprehensively from both theoretical and practical perspectives, and it establishes important new conceptual frameworks to guide the development of this emerging field. It provides an introduction to the current state of neuroprosthetics and expected future trends, along with an introduction to fundamental principles of information security and an analysis of why they must be re-envisioned to address the unique challenges posed by advanced neuroprosthetics. A device ontology for neuroprosthetics is formulated, and a two-dimensional cognitional security framework is developed whose security goals are designed to protect a device's human host in his or her roles as a sapient metavolitional agent, embodied embedded organism, and social and economic actor. Practical consideration is given to information security responsibilities and to management, operational, and technical controls. Finally, a biocybernetic model is developed for classifying neuroprosthetic devices according to their participation in the neural activity of their human hosts.