Abstract: Incoming signals that are sparse in the code-correlation domain, such as CDMA signal (GPS signals being a specific example of such signals) are processed by sampling the incoming signal at irregular time intervals at an average rate that is significantly lower than the Nyquist rate; which in the case of GPS signals is the chip rate of a pseudorandom code sequence that is embedded in the signal. The sampled signal is processed with locally generated signals that are also sampled the same irregular time intervals.

Abstract: Incoming signals that are sparse in the code-correlation domain, such as CDMA signal (GPS signals being a specific example of such signals) are processed by sampling the incoming signal at irregular time intervals at an average rate that is significantly lower than the Nyquist rate; which in the case of GPS signals is the chip rate of a pseudorandom code sequence that is embedded in the signal. The sampled signal is processed with locally generated signals that are also sampled the same irregular time intervals.

Abstract: Media authentication is facilitated. In connection with an example embodiment, media is authenticated using an encoded projection of the media that is decoded using the media as an input. A condition of authenticity of the media is determined based upon an indication of distortion of the media characterized by a decoding of the encoded projection.