Transmitting apparatus, receiving apparatus, and data transmission system

A transmitting method comprising:

• an encrypting step of encrypting a part or all of data in accordance with a predetermined rule and outputting the encrypted data;
• a data extracting step of extracting predetermined data from said data;
• an arithmetic operating step of executing a predetermined arithmetic operation to said predetermined data extracted in said data extracting step and outputting arithmetic operation resultant data;
• and
• a data inserting step of inserting said arithmetic operation resultant data to an output in said encrypting step and transmitting the resultant data to a transmission path.

A receiving apparatus which receives data on a transmission path obtained by encrypting a part or all of data in accordance with a predetermined rule, outputting the encrypted data, extracting predetermined data from said data, executing a predetermined arithmetic operation to the extracted predetermined data, obtaining arithmetic operation resultant data as a result of said arithmetic operation, inserting said arithmetic operation resultant data to said encryption output, and transmitting the resultant encryption data to said transmission path, comprising:

• first data extracting means for extracting data corresponding to said arithmetic operation resultant data from the data received through said transmission path;
• decrypting means for decrypting the encryption of said received data on the basis of a predetermined rule and outputting the decrypted data;
• second data extracting means for extracting data corresponding to said predetermined data from an output of said decrypting means;
• arithmetic operating means for executing the same arithmetic operation as said arithmetic operation to the data which corresponds to said predetermined data and has been extracted by said second data extracting means;
• comparing means for comparing the data extracted by said first data extracting means with arithmetic operation resultant data from said arithmetic operating means;
• and
• switching means for switching the output of said decrypting means and another output in accordance with a comparison result of said comparing means.

A receiving method which receives data on a transmission path obtained by encrypting a part or all of data in accordance with a predetermined rule, outputting the encrypted data, extracting predetermined data from said data, executing a predetermined arithmetic operation to the extracted predetermined data, obtaining arithmetic operation resultant data as a result of said arithmetic operation, inserting said arithmetic operation resultant data to said encryption output, and transmitting the resultant encryption data to said transmission path, comprising:

• a first data extracting step of extracting data corresponding to said arithmetic operation resultant data from the data received through said transmission path;
• a decrypting step of decrypting the encryption of said received data on the basis of a predetermined rule and outputting the decrypted data;
• a second data extracting step of extracting data corresponding to said predetermined data from an output of said decrypting step;
• an arithmetic operating step of executing the same arithmetic operation as said arithmetic operation to the data which corresponds to said predetermined data and has been extracted in said second data extracting step;
• a comparing step of comparing the data extracted in said first data extracting step with an arithmetic operation result in said arithmetic operating step;
• and
• a switching step of switching the output in said decrypting step and another output in accordance with a comparison result in said comparing step.

A transmitting apparatus comprising:

• first encrypting means for encrypting a part or all of data by using a first key and outputting the encrypted data;
• data extracting means for extracting predetermined data from said data on the basis of random numbers generated in accordance with a predetermined rule in accordance with random number control information;
• arithmetic operating means for executing a predetermined arithmetic operation to said predetermined data extracted by said data extracting means and outputting arithmetic operation resultant data;
• second encrypting means for encrypting said arithmetic operation resultant data by using a second key and outputting the encrypted data;
• and
• data inserting means for inserting an output of said second encrypting means to an output of said first encrypting means and transmitting the resultant data to a transmission path.

A transmitting method comprising:

• a first encrypting step of encrypting a part or all of data by using a first key and outputting the encrypted data;
• a data extracting step of extracting predetermined data from said data on the basis of random numbers generated in accordance with a predetermined rule in accordance with random number control information;
• an arithmetic operating step of executing a predetermined arithmetic operation to said predetermined data extracted in said data extracting step and outputting arithmetic operation resultant data;
• a second encrypting step of encrypting said arithmetic operation resultant data in accordance with a predetermined rule by using a second key and outputting the encrypted data;
• and
• a data inserting step of inserting an output in said second encrypting step to an output in said first encrypting step and transmitting the resultant data to a transmission path.

A receiving apparatus which receives data on a transmission path obtained by encrypting a part or all of data by using a first key in accordance with a predetermined rule, outputting the encrypted data, extracting predetermined data from said data on the basis of random numbers generated in accordance with a predetermined rule in accordance with random number control information, executing a predetermined arithmetic operation to the extracted predetermined data, encrypting arithmetic operation resultant data as a result of said arithmetic operation by using a second key in accordance with a predetermined rule, inserting the encrypted arithmetic operation resultant data to said encryption output, and transmitting the resultant encryption data to said transmission path, comprising:

• first data extracting means for extracting data corresponding to said encrypted arithmetic operation resultant data from the data received through said transmission path;
• first decrypting means for decrypting said encrypted arithmetic operation resultant data extracted by said first data extracting means by using a third key in accordance with a predetermined rule;
• second decrypting means for decrypting the encryption formed by using said first key of said received data by using a fourth key in accordance with a predetermined rule and outputting the decrypted data;
• second data extracting means for extracting data corresponding to said predetermined data from the output of said second decrypting means on the basis of the random numbers generated in accordance with the predetermined rule in accordance with the random number control information;
• arithmetic operating means for executing the same arithmetic operation as said arithmetic operation to the data which corresponds to said predetermined data and has been extracted by said second data extracting means;
• comparing means for comparing said arithmetic operation resultant data decrypted by said first decrypting means with arithmetic operation resultant data from said arithmetic operating means;
• and
• switching means for switching the output of said second decrypting means and another output in accordance with a comparison result of said comparing means.

A receiving method which receives data on a transmission path obtained by encrypting a part or all of data by using a first key in accordance with a predetermined rule, outputting the encrypted data, extracting predetermined data from said data on the basis of random numbers generated in accordance with a predetermined rule in accordance with random number control information, executing a predetermined arithmetic operation to the extracted predetermined data, encrypting arithmetic operation resultant data as a result of said arithmetic operation by using a second key in accordance with a predetermined rule, inserting the encrypted arithmetic operation resultant data to said encryption output, and transmitting the resultant encryption data to said transmission path, comprising:

• a first data extracting step of extracting data corresponding to said encrypted arithmetic operation resultant data from the data received through said transmission path;
• a first decrypting step of decrypting said encrypted arithmetic operation resultant data extracted in said first data extracting step by using a third key in accordance with a predetermined rule;
• a second decrypting step of decrypting a part or all of encryption formed by using said first key of said received data by using a fourth key in accordance with a predetermined rule and outputting the decrypted data;
• a second data extracting step of extracting data corresponding to said predetermined data from the output of said second decrypting step on the basis of the random numbers generated in accordance with the predetermined rule in accordance with the random number control information;
• an arithmetic operating step of executing the same arithmetic operation as said arithmetic operation to the data which corresponds to said predetermined data and has been extracted in said second data extracting step;
• a comparing step of comparing said arithmetic operation resultant data decrypted in said first decrypting step with arithmetic operation resultant data in said arithmetic operating step;
• and
• a switching step of switching the output of said second decrypting step and another output in accordance with a comparison result in said comparing step.