An application of direct spread spectrum techniques for a tape recording autlienticator
RJ Prandolini, Michael P. Moody · 1st IASTED International Symposium on Signal Processing and its Applications · 1987
The authentication of audio tape recordings ensures that no editing or alterations have occurred. This may be achieved by encoding a parameter of the original signal in a secure process, at the time of recording, which is later decoded to validate the recorded audio. This paper discusses a proposed authenticating systems that adds a pn-sequence to the audio signal. The recorded signal can be authenticated by despreading the pn-sequence via fast convolution, and the resulting data used to authenticate the audio. The pn-sequence is removed from the recorded signal by a fast circular convolution least-mean-squares adaptive filter. The implementation of these two algorithms by the TMS320 family of digital signal processors is discussed.