708
7 Countermeasures Against Hardware Trojans
Power on
Microcircuit configuration by product from the
development example (authentication unit +
user project)
Authentification block generates an array of
random numbers
Authentication unit writes the generated array of
random numbers into DS28E01 EPROM
Authentication unit reads the unique
identification number from DS28E01
DS28E01 calculates MAC in accordance with the
SHA-1 algorithm
Authentication unit reads MAC from DS28E01
Authentication unit calculates MAC in accordance
with the SHA-1 algorithm
Authentication unit compares two MACs
Coincidence
No
Yes
Operation of the user project is
enabled
Operation of the user
project remains
disabled
Algorithm of project protection using SHA-1
Fig. 7.23 Operation algorithm of the authentication block in case of implementation of the IFF
concept [97]