1. A system for detecting and classifying a security breach, the system comprising: at least one sensor configured to detect seismic vibration from a source, and to generate an output signal that represents the detected seismic vibration; and a controller configured to extract a feature vector from the output signal of the sensor and to compute one or more likelihoods of the extracted feature vector relative to set {b i } (i=1,. .. , i max ) of breach classes b i , the controller further configured to classify the source of the detected seismic vibration as a security breach belonging to one of the breach classes b i by choosing a breach class within the set {b i } that has a maximum likelihood relative to the extracted feature vector.