Selective encryption for consumer applications

Selective encryption is a technique to save computational complexity or enable new system functionality by encrypting only a portion of a compressed bitstream while achieving adequate security. Although suggested in a number of specific cases, selective encryption could be much more widely used in consumer electronic applications, ranging from mobile multimedia terminals to digital cameras, were it subjected to a more thorough security analysis. We describe selective encryption and develop a simple scalar quantizer example to demonstrate the power of the concept, list a number of potential consumer electronics applications, then describe an appropriate method for developing and analyzing selective encryption for particular compression algorithms. We summarize results from the application of this method to the MPEG-2 video compression algorithm.