Patent ID: 7835524

Claim:
A data transmitting apparatus for encrypting information data by using predetermined key information and for performing secret communication with a receiving apparatus, the data transmitting apparatus comprising: a multi-level code generation section for generating, based on the predetermined key information, a multi-level code sequence in which a signal level changes so as to approximately represent random numbers; a multi-level processing section for combining the multi-level code sequence and the information data, and generating a multi-level signal having a plurality of levels corresponding to the combination of the multi-level code sequence and the information data; and a modulator section for performing predetermined modulation processing on the multi-level signal, and outputting a modulated signal, wherein the multi-level code generation section includes: a random number sequence generation section for generating, based on the predetermined key information, a plurality of modulation pseudo-random number sequences; and a multi-level conversion, into which a plurality of bit sequences including at least part of the plurality of modulation pseudo-random number sequences is inputted as an input bit sequence, for converting the input bit sequence into the multi-level code sequence, wherein the input bit sequence inputted into the multi-level conversion section is greater in a number of digits than each of the plurality of modulation pseudo-random number sequences generated by the random number sequence generation section, and wherein the multi-level processing section allocates different values of the information data to adjoining multi-levels of the multi-level signal.