Random number generating, encrypting, and decrypting apparatus, method thereof, program thereof, and recording medium thereof

A method of operating a random number generating apparatus that uses a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs the method comprising:

• when the outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.

A non-transitory computer readable recording medium on which a program that causes a computer to execute a random number generating method has been recorded, the program using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs, the random number generating method comprising:

• when the outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.

An encrypting apparatus that:

• (a) exclusively ORs plain text and a random number;
• and (b) generates cipher text, the encrypting apparatus comprising:
• a random number generating device that generates the random number, the random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells one-dimensionally arranged, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule;
• a path that outputs an output of at least one of the plurality of cells and feeds back outputs of the plurality of cells to inputs of the plurality of cells at the current time so as to update the state values of the plurality of cells at the next time, the plurality of cells including inputs and outputs;
• and
• a switching circuit, disposed in the path, configured to:
• (a) for a first key stream output, shift the output of each the cell by a first predetermined number of cells and feed the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• and
• (b) after the first key stream is output, change the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shift the output of each the cell by the second predetermined number of cells and feed the shifted outputs to inputs of other cells.

A method of operating an encrypting device by exclusively ORing plain text and a random number and generating cipher text, the method comprising:

• generating the random number using a random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs;
• when the outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.

A non-transitory computer readable recording medium on which a program that causes a computer to execute an encrypting method of exclusively ORing plain text and a random number and generating cipher text has been recorded, the encrypting method comprising:

• generating the random number using a random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality, of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs;
• and
• when the outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.

A decrypting apparatus that:

• (a) exclusively ORs cipher text and a random number;
• and decrypts the cipher text, the decrypting apparatus comprising:
• a random number generating device that generates the random number, the random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells one-dimensionally arranged, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule;
• a path that outputs an output of at least one of the plurality of cells and feeds back outputs of the plurality of cells to inputs of the plurality of cells at the current time so as to update the state values of the plurality of cells at the next time, the plurality of cells including inputs and outputs;
• and
• a switching circuit, disposed in the path, configured to:
• (a) for a first key stream output, shift the output of each the cell by a first predetermined number of cells and feed the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, change the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shift the output of each the cell by the second predetermined number of cells and feed the shifted outputs to inputs of other cells.

A method of operating a decrypting apparatus by exclusively ORing cipher text and a random number and decrypting cipher text, the method comprising:

• generating the random number using a random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs;
• and
• when the outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.

A non-transitory computer readable recording medium on which a program that causes a computer to execute a decrypting method of exclusively ORing cipher text and a random number and decrypting cipher text has been recorded, the decrypting method comprising:

• generating the random number using a random number generating device using a one-dimensional, two-state, and K-neighbor cell automaton having a plurality of cells, each cell having a state value that is 0 or 1, the state value of each cell at next time being given by a rule that depends on only the state value of the own cell and the state values of neighbor cells, the state value of each cell being updated according to the rule, the plurality of cells including inputs and outputs;
• and
• when the output and outputs of each of the plurality of cells are fed back to inputs of other cells at the current time so as to update the state values of the plurality of cells at the next time:
• (a) for a first key stream output, shifting the output of each of the plurality of cells by a first predetermined number of cells and feeding the shifted outputs to inputs of other cells, the first predetermined number being at least two;
• (b) after the first key stream is output, changing the first predetermined number to a second predetermined number;
• and
• (c) for a second key stream output, shifting the output of each the cell by the second predetermined number of cells and feeding the shifted outputs to inputs of other cells.