Patent ID: 8189787

Claim:
A data transmitting apparatus for performing cipher communication, the data transmitting apparatus comprising: a memory; a multi-level encoding section for receiving predetermined key information and information data, and for generating a multi-level signal in which a signal level changes so as to be approximately random numbers; and a modulation section for generating a modulated signal in a predetermined modulation format in accordance with the multi-level signal, wherein the multi-level encoding section includes: a multi-level code generation section for generating, by using the predetermined key information, a multi-level code sequence in which a signal level changes so as to be random numbers; and a multi-level processing section for combining the multi-level code sequence and the information data in accordance with predetermined processing, and for generating the multi-level signal having a level corresponding to a combination of the multi-level code sequence and the information data, the multi-level code generation section includes: a random number sequence generation section for generating a binary random number sequence by using the predetermined key information; and a multi-level conversion section for generating the multi-level code sequence from the binary random number sequence in accordance with a predetermined encoding rule, and the predetermined encoding rule specifies that binary bit sequences respectively having predetermined lengths are caused to correspond to respective multi levels of the multi-level code sequence uniquely, and that a number of digits having different bits as a hamming distance between any adjoining binary bit sequences, which are allocated to arbitrary adjoining multi levels, is equal to the length of each of the binary bit sequences, or equal to a value less than the length of each of the binary bit sequences by 1 bit.