  This paper is concerned with identifying linear system dynamics without the
knowledge of individual system trajectories, but from the knowledge of the
system's reachable sets observed at different times. Motivated by a scenario
where the reachable sets are known from partially transparent manufacturer
specifications or observations of the collective behavior of adversarial
agents, we aim to utilize such sets to determine the unknown system's dynamics.
This paper has two contributions. Firstly, we show that the sequence of the
system's reachable sets can be used to uniquely determine the system's dynamics
for asymmetric input sets under some generic assumptions, regardless of the
system's dimensions. We also prove the same property holds up to a sign change
for two-dimensional systems where the input set is symmetric around zero.
Secondly, we present an algorithm to determine these dynamics. We apply and
verify the developed theory and algorithms on an unknown band-pass filter
circuit solely provided the unknown system's reachable sets over a finite
observation period.
