Security of Safety Important I&C Systems - Nuclear Power Plant Instrumentation and Control Systems for Safety and Security - page 249

Figure 7. Taxonomy of hardware trojans

• Speciication: At this stage designers de-
termine main chip characteristics (for ex-
ample, its target environment, expected
functionality, physical size, power con-
sumption and delays), therefore, a modi-
ication of such characteristics makes
possible modiication of functional speci-
ications and design constraints (for exam-
ple, timing requirements).
• Design: At this stage developers specify
functional, logic, timing, and physical con-
straints so that a chip will conform to target
technology, therefore, application of third-

party vendor IP-cores and standard cells
becomes possible during development
process; so, HTs can be present in any of
components that were used in chip devel-
opment process;
• Chip Fabrication: At this stage a set of
masks, using wafers, is created; even sub-
tle mask modiications can seriously afect
chip functionality;
• Chip Testing: This stage provides poten-
tial possibilities for HT detection inserted
during previous LC stages of a chip;