The need for highly secure, highly dependable computer systems is acute in today's world. As an example, the United States' President's Commission on Critical Infrastructure Protection identifies the nation's electrical, transportation, telecommunication, and financial systems as critical points, all of which heavily depend on computer technology [1].However, frequently security and fault-tolerance are looked at in isolation to each other, as two separate issues. We contend that there are areas where the two's goals and methods overlap, and that there is a large benefit to be gained by examining the two in relation to one another. This paper details our reasons for this viewpoint and points out a few examples where it has born fruit, as well as presenting some of the research challenges that remain to be addressed.