JTAG Combined Attack
Résumé
The combined attacks are widely spread in the
domain of smart cards and microcontrollers but they have not
been yet democratized on complex embedded microprocessors
such as those which can be found in smart phones, tablets
and automotive systems. The main reason behind this is the
complexity to inject a fault at the right place and at the right
time to make these attacks effective on such devices. However
for development and debug, these devices provide new tools that
could be considered as potential ways for attacks. It’s the case
of the JTAG debug tool which is present on most electronic
devices today. The improper use of this latter is already known
but in this paper we present a new misuse of this one: the JTAG
as a fault injection tool. Through an example, we explain how
this tool can be used to perform a combined attack.