Advanced audio steganography technology is finally available with AudioWatermark.
Now you can hide information into the audio signal itself and recover it after transmission. Cut and paste manipulations by third parties are also detected.
The complete audio watermarking scenario passes through three successive stages.
Watermark insertion
The secret information is merged with the carrier audio signal while keeping the acoustic properties unaffected for the Human Hearing System, i.e. the watermark cannot be detected by listening the audio.
The information is not dependent in any way to the audio file or digital representation; the watermark is embedded into the audio signal itself, not just hidden into the file’s bits.
Data transmission
The audio signal carrying the hidden info is transmitted through a communication channel. This channel is an abstraction for all the degradations and attacks the watermark may suffer before extraction.
Possible attacks are: physical transmission through a noisy audio channel, digital to analog conversions, on air recording, resampling, recoding, lossy compression, cut and paste manipulations, etc.
Ideally, the watermark should survive to all those attacks.
Watermark extraction
The audio signal is processed at destination by a forensic tool that rebuilds and extracts the hidden information embedded in the first stage. Just the authorized user can extract the information.
If segments of the audio have been manually deleted, added or moved, the manipulation is detected.
AudioWatermark features
Real audio steganography
Information is hidden into the actual audio signal, not at file or digital stream level.
Inaudible watermark
Watermarked audio can’t be distinguished from the original by the Human Hearing System.
Audio integrity verification
Cut and paste attacks in the watermarked audio are detected.
Watermark information is secret
Information can’t be read, removed or modified by third parties.
API for on-premise solutions
Efficient enough even for embedded systems.
Robust to D/A/D conversions
Watermark can survive analog playing through loudspeakers + on air recording + sampling back to digital.
Robust to lossy compression
Watermark can survive MP3 and similar lossy codecs.
Robust to resampling
Watermark can survive sampling frequency (KHz) and bit depth (bits per sample) conversions.
Robust to noisy channels
Watermark can survive transmission through telephone lines and radio broadcasts.
Applications
Audio steganography is more than sending secret messages.