Detection of laser-based audio injection attacks using channel cross correlation

At least one non-transitory machine-readable storage medium having instructions encoded thereon that, when executed by one or more processors, cause a process to be carried out for prevention of laser-based audio attacks, the process comprising:

• calculating a time alignment metric based on time delays associated with peaks of cross correlations between signals received from a plurality of microphones of an array of microphones;
• calculating a similarity metric based on magnitudes associated with the peaks of the cross correlations;
• generating a first attack indicator based on the time alignment metric;
• generating a second attack indicator based on the similarity metric;
• and
• providing warning of a laser-based audio attack based on the first attack indicator and/or the second attack indicator.

A system for prevention of laser-based audio attacks, the system comprising:

• a cross correlation circuit to calculate cross correlations between signals received from a plurality of microphones of an array of microphones;
• a peak finding circuit to identify time delays associated with peaks of the cross correlations and magnitudes associated with the peaks of the cross correlations;
• a time alignment circuit to calculate a time alignment metric based on the time delays;
• a similarity metric circuit to calculate a similarity metric based on the magnitudes;
• a thresholding circuit to generate a first attack indicator based on a comparison of the time alignment metric to a first threshold and to generate a second attack indicator based on a comparison of the similarity metric to a second threshold;
• and
• an attack notification circuit to provide warning of a laser-based audio attack based on the first attack indicator and/or the second attack indicator.