Abstract: Two data units are selected from main information, such as MIDI data, into which additional information is to be incorporated, to calculate a difference between respective values of the two data units. A particular data segment to be incorporated into one of the MIDI data units is selected from a group of data of additional information. The size of the data segment to be incorporated into one of the data units may be either one bit or two or more bits. Substitute data to replace the content of one MIDI data unit is generated on the basis of a predetermined function using, as variables, the data-related value and a value of the particular data segment, and the content of the data unit corresponding to a predetermined one of the two MIDI data units is replaced by the generated substitute data. Thus, through such an electronic watermarking technique, any desired additional information can be incorporated into the MIDI data without changing the MIDI data format.

Abstract: Two data units are selected from main information, such as MIDI data, into which additional information is to be incorporated, to calculate a difference between respective values of the two data units. A particular data segment to be incorporated into one of the MIDI data units is selected from a group of data of additional information. The size of the data segment to be incorporated into one of the data units may be either one bit or two or more bits. Substitute data to replace the content of one MIDI data unit is generated on the basis of a predetermined function using, as variables, the data-related value and a value of the particular data segment, and the content of the data unit corresponding to a predetermined one of the two MIDI data units is replaced by the generated substitute data. Thus, through such an electronic watermarking technique, any desired additional information can be incorporated into the MIDI data without changing the MIDI data format.

Abstract: Two data units are selected from main information, such as MIDI data, into which additional information is to be incorporated, to calculate a difference between respective values of the two data units. A particular data segment to be incorporated into one of the MIDI data units is selected from a group of data of additional information. The size of the data segment to be incorporated into one of the data units may be either one bit or two or more bits. Substitute data to replace the content of one MIDI data unit is generated on the basis of a predetermined function using, as variables, the data-related value and a value of the particular data segment, and the content of the data unit corresponding to a predetermined one of the two MIDI data units is replaced by the generated substitute data. Thus, through such an electronic watermarking technique, any desired additional information can be incorporated into the MIDI data without changing the MIDI data format.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: A certification method realized by a certification server is applied to a networking system containing at least one local network connecting together terminals that constitute a same group to share a local session therebetween. When one terminal requests certification, the certification server sends an inter-group ID to the terminal while sending an authentication request to each of the other terminals of the same group. Then, the certification server determines to perform certification on the terminal based on results of authentication that is performed by each of the users of the other terminals in a face-to-face manner. Herein, the certification server can determine whether to certify the terminal based on secret information, which are disassembled and allocated to the terminals respectively. Thus, it is possible to reliably perform certification and authentication on terminals and users.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: Two data units are selected from main information, such as MIDI data, into which additional information is to be incorporated, to calculate a difference between respective values of the two data units. A particular data segment to be incorporated into one of the MIDI data units is selected from a group of data of additional information. The size of the data segment to be incorporated into one of the data units may be either one bit or two or more bits. Substitute data to replace the content of one MIDI data unit is generated on the basis of a predetermined function using, as variables, the data-related value and a value of the particular data segment, and the content of the data unit corresponding to a predetermined one of the two MIDI data units is replaced by the generated substitute data. Thus, through such an electronic watermarking technique, any desired additional information can be incorporated into the MIDI data without changing the MIDI data format.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: A certification method realized by a certification server is applied to a networking system containing at least one local network connecting together terminals that constitute a same group to share a local session therebetween. When one terminal requests certification, the certification server sends an inter-group ID to the terminal while sending an authentication request to each of the other terminals of the same group. Then, the certification server determines to perform certification on the terminal based on results of authentication that is performed by each of the users of the other terminals in a face-to-face manner. Herein, the certification server can determine whether to certify the terminal based on secret information, which are disassembled and allocated to the terminals respectively. Thus, it is possible to reliably perform certification and authentication on terminals and users.

Abstract: Performance data is generated by performing in real time a music piece starting at a desired performance position. Performance position, in the music piece, of the real-time performance data is estimated from reference performance data of the music piece. Performance data to be performed following the estimated position is identified, and accuracy of the estimated position is determined in accordance with whether performance data corresponding to the identified performance data is generated as next real-time performance data. Because the accuracy of the estimated position is determined after generation of the next real-time performance data, a performance position following the estimated position determined as accurate represents a current performance position. Score based on the reference performance data is shown on a display, and the current performance position in the real-time performance is indicated on the displayed score.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: Arrangement/order of data in main information is changed in accordance with a value of additional information and with a predetermined encoding algorithm, and thus an electronic watermark of the additional information is embedded in the form of a change in the arrangement/order of the data without values of the data in the main information being changed. Time information of a plurality of performance data in the main information may be changed in accordance with the value of the additional information so that an electronic watermark of the additional information is embedded in the form of a combination of changes of the time information. Control may be made as to whether particular status information in music performance data should be used or not so that a one-bit electronic watermark corresponding to the use/non-use of the particular status information is embedded.

Abstract: Two data units are selected from main information, such as MIDI data, into which additional information is to be incorporated, to calculate a difference between respective values of the two data units. A particular data segment to be incorporated into one of the MIDI data units is selected from a group of data of additional information. The size of the data segment to be incorporated into one of the data units may be either one bit or two or more bits. Substitute data to replace the content of one MIDI data unit is generated on the basis of a predetermined function using, as variables, the data-related value and a value of the particular data segment, and the content of the data unit corresponding to a predetermined one of the two MIDI data units is replaced by the generated substitute data. Thus, through such an electronic watermarking technique, any desired additional information can be incorporated into the MIDI data without changing the MIDI data format.

Abstract: Performance data is generated by performing in real time a music piece starting at a desired performance position. Performance position, in the music piece, of the real-time performance data is estimated from reference performance data of the music piece. Performance data to be performed following the estimated position is identified, and accuracy of the estimated position is determined in accordance with whether performance data corresponding to the identified performance data is generated as next real-time performance data. Because the accuracy of the estimated position is determined after generation of the next real-time performance data, a performance position following the estimated position determined as accurate represents a current performance position. Score based on the reference performance data is shown on a display, and the current performance position in the real-time performance is indicated on the displayed score.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. For reproduction of the additional information, the stored main information is read out, and the individual data pieces are reproduced from the particular data units by inversely executing the algorithm.