supplies, which sometimes can provide insight into key values and algorithms
inside of a closed container the way seismography charts the inside of the earth, or as CAT
scans and NMR map the inside of living organisms)
behaviour of the system
other device to impersonate the SNC. However, a great deal of other information from inside
the SNC also has value, and must be protected.
design must consider and counter them, but the manufacturing process itself is also subject to
sabotage or simple mismanagement. For instance, if a component is substituted or a process
altered during assembly, the security of the system can be compromised. This is especially
significant, since complex devices such as the SNC and its subassemblies cannot be fully
inspected and tested once they are assembled. It is imperative, for the highest level of security,
to perform inspections and testing during the manufacturing operation, and not only at the end.
Security cannot be assured merely by inspection and testing at the end. Security comes from
control of the entire programming operation, including design and coding reviews and
inspection at all phases of development. It also requires the fundamental process of ascertaining
that the assured software is, in fact, the software loaded into the SNC, and not a substitute
program.
document. In general, they might be characterized by the following:
end, the software should do what is intended to do, and should not exhibit any form of
undesirable, unintended behaviour or other errors)
the likelihood of failure (every superfluous feature is an opportunity for failure or sabotage)
team member as potentially hostile