Systems and associated methods for detecting a set of spectrum sensing falsification (SSF) attacks in a geographic database (GDB) driven cognitive radio (CR) system. Viewing the GDB as a type of non-orthogonal compressive sensing (CS) dictionary, the composite power spectral density (PSD) estimate at a candidate CR is approximated by a small number of sensor nodes listed in the GDB. In a dense CR network, the PSD estimate at a CR may contain a composite mixture of spectrally overlapping signals. An implementation of an optimized, greedy algorithm orthogonal matching pursuit (OMP) returns a set of sensor nodes which are suspected to be in the vicinity of the CR. A sufficient match between the PSD estimate reported by a candidate CR and the PSD that is sparsely approximated from the SNs in its area provides confidence (trust) metrics which may be used to detect potential SSF attacks.