6.8 Practical Examples of Implementation …
623
6.8 Practical Examples of Implementation of Circuit-Based
Methods of Microcircuit Protection
from Re-engineering
Due to the specifics of this direction formulated in Sect. 6.7.1, there are not so
many circuitry-based methods of protection published in scientific periodic materials.
This is understandable—after all, intruders also closely monitor all new technical
solutions in this field, and thus microcircuit developers are not willing to openly
publish corresponding technical solutions.
In this case, authors are no exception and thus present a number of their own
technical solutions used by them for protection of microcircuits that are currently
out of production.
The main idea of such circuitry-based solutions can be briefly formulated as
follows.
A non-standard element (block, fragment) with original and previously unpublished properties is implemented in the microcircuit design during the engineering
stage. This element shall be implemented in a standard technological process; its
production requires no additional operations or changes in the process production
modes (impurity concentrations, doping levels, and doses, anneal time, etc.).
This element shall perform one or several specific logic functions or affect reliability of functioning of the circuit in real operation conditions, e.g., be responsible
for the function of protection from static discharges.
At the same time, it shall not occupy a lot of place on the chip topology, while
the physical mechanism of its operation shall be different from all previously known
elements of this class.
If the intruder fails to understand the operating principle of such element, in the
first case such microcircuit cloned by the intruder will not correspond to its prototype
in terms of functionality; in the second case, it can fail on the board in real operating
conditions, e.g., under the effect of static discharge.
6.8.1 Integrated Implementation of Embedded Power Control
Circuit
Developers of onboard electronic systems face, among many other issues, the
problem of controlling the power supply and setting the functional blocks of the
system in the original (initial) state during power-on. Actually, after power is
supplied, all triggers in the central processor are set to an arbitrary state, after which
the processor or a separate microcontroller can start performing some chaotic actions,
reading arbitrary codes perceived by the control device as instructions from the
command memory.
This situation also occurs in case of a short-term disconnection (failure) of the
onboard supply voltage. As a rule, this problem is solved by using special devices
623
6.8 Practical Examples of Implementation of Circuit-Based
Methods of Microcircuit Protection
from Re-engineering
Due to the specifics of this direction formulated in Sect. 6.7.1, there are not so
many circuitry-based methods of protection published in scientific periodic materials.
This is understandable—after all, intruders also closely monitor all new technical
solutions in this field, and thus microcircuit developers are not willing to openly
publish corresponding technical solutions.
In this case, authors are no exception and thus present a number of their own
technical solutions used by them for protection of microcircuits that are currently
out of production.
The main idea of such circuitry-based solutions can be briefly formulated as
follows.
A non-standard element (block, fragment) with original and previously unpublished properties is implemented in the microcircuit design during the engineering
stage. This element shall be implemented in a standard technological process; its
production requires no additional operations or changes in the process production
modes (impurity concentrations, doping levels, and doses, anneal time, etc.).
This element shall perform one or several specific logic functions or affect reliability of functioning of the circuit in real operation conditions, e.g., be responsible
for the function of protection from static discharges.
At the same time, it shall not occupy a lot of place on the chip topology, while
the physical mechanism of its operation shall be different from all previously known
elements of this class.
If the intruder fails to understand the operating principle of such element, in the
first case such microcircuit cloned by the intruder will not correspond to its prototype
in terms of functionality; in the second case, it can fail on the board in real operating
conditions, e.g., under the effect of static discharge.
6.8.1 Integrated Implementation of Embedded Power Control
Circuit
Developers of onboard electronic systems face, among many other issues, the
problem of controlling the power supply and setting the functional blocks of the
system in the original (initial) state during power-on. Actually, after power is
supplied, all triggers in the central processor are set to an arbitrary state, after which
the processor or a separate microcontroller can start performing some chaotic actions,
reading arbitrary codes perceived by the control device as instructions from the
command memory.
This situation also occurs in case of a short-term disconnection (failure) of the
onboard supply voltage. As a rule, this problem is solved by using special devices