Robust authentication of digital audio

A system for authenticating digital audio, the system comprising:

• a processor;
• and
• a computer-readable medium storing instructions that are operative upon execution by the processor to:
• receive a digital audio file;
• generate a first watermark using a first key, wherein the first watermark is band-limited to a first bandwidth;
• generate a second watermark using a second key, wherein the second watermark is band-limited to a second bandwidth, and wherein the second bandwidth does not overlap with the first bandwidth;
• embed the first watermark into a segment of the digital audio file;
• and
• embed the second watermark into the segment of the digital audio file.

One or more computer storage devices having computer-executable instructions stored thereon, which, on execution by a computer, cause the computer to perform operations comprising:

• receiving a digital audio file;
• determining a first watermark score of a segment of the digital audio file for a first watermark using a first key, wherein the first watermark is band-limited to a first bandwidth;
• determining a second watermark score of the segment of the digital audio file for a second watermark using a second key, wherein the second watermark is band-limited to a second bandwidth, and wherein the second bandwidth does not overlap with the first bandwidth;
• based on at least the first watermark score and the second watermark score, determining a probability that the digital audio file is watermarked;
• and
• based on at least determining the probability that the digital audio file is watermarked, generating a report indicating whether the digital audio file is watermarked.