Patent ID: 7245721
Filing Date: 2007-07-17
Classification: G11B

Abstract:
1. An apparatus for generating digital audio data comprising a source of digital audio signals, and a data encoding device having: a serial data input; an encoded serial data output; a random number generator which generates a stream of random bits; a transformation unit comprising means for storing a predetermined number of values of the random bit to derive a multiple bit random word; a permutation unit which generates an initial plurality of encoding bits from the multiple bit random word; and an encoding unit which combines each bit input on the serial data input with a plurality of additional encoding bits forming an encryption key, to derive an encoded output bit and an updated encryption key comprising a plurality of updated encodes bits, wherein an initial bit input on the serial data input is encoded with an encryption key comprising the initial plurality of encoding bits output by the permutation unit and each subsequent input bit is encrypted using an updated key which is derived from previous values of the encryption key and of the input bit, and wherein over time the encoded output bit stream comprises substantially white noise.