328 Communication Architectures for SoC
simple side-channel attacks. The “simple” refers to the number of measure-
ments used and not to the simplicity of the attacks. In fact, they require a
precise knowledge of the architecture and implementation of both the device
and the algorithm and their effect on the observed measurement sample. As a
result, they are relatively easy to protect from. For instance, the square-and-
multiply algorithm can be implemented to perform the multiply independent
of the exponent bit and only use the result if the exponent bit is actually one.
Attacks that use many observations are referred to as differential side-
channel attacks. The timing attacks typically target variable instruction flow.
The power attacks, and for that ...