The formidable difficulty in securing systems stems in large part from the increasing complexity of the systems we build but also the degree to which we now depend on information systems. Complex systems cannot be fully verified under all possible conditions. Self-Cleansing Intrusion Tolerance (SCIT) servers go through periodic cleaning. SCIT can be used to create secure and robust cluster of servers without the impossible requirement of having perfect security on each server in the cluster. In this paper, we identify six SCIT security primitives that must be satisfied. We present a SCIT hardware enhanced (SCIT/HES) implementation that guarantees the incorruptibility of SCIT operations.