Security Issues in SoC Communication 383
an example, Tiri et al. [119] show the measurements and the attack result of
an AES ASIC protected using WDDL to flatten out the power consumption.
1.5M measurements are not sufficient to find the key byte under attack.
Algorithmic masking was conceived as a mathematically proven counter-
measure, but recent developments show that practical implementation issues
can often break perfect theoretical security schemes. Earlier work has already
shown that it was vulnerable against higher order attacks. These attacks can
combine multiple samples to remove an unknown mask because of the Ham-
ming weight or distance leakage estimation model used [93]. But now, using
template attacks, in which the leakage model is built