The conventional idea of analog computing has recently been revived by recent developments of the fields of metamaterials and ultrafast optics, allowing one to perform signal-processing tasks at the speed of wave propagation with high efficiency. Despite these advantageous features, the functionality of such wave-based computing systems, like any other analog system, is mitigated by the sensitivity and geometrical tolerances of analog components, causing uncertainties in the computation process. Here, we propose the possibility of significantly enhancing the reliability of wave-based computing by leveraging the protection of topological insulators. We believe that our theoretical and experimental findings open the venue for further explorations that unify the field of topological insulators with the fields of linear system theory and signal processing.