File generation method, file generation apparatus, and non-transitory computer-readable storage medium for storing program

1. A method for generating a file, the method comprising:

executing a reception process that includes receiving text information;

executing a first generation process that includes

obtaining one or more of detected phrases by detecting a phrase of a specific type from among the received text information,

generating, for a respective detected phrase, encoded information by converting the respective detected phrase into a corresponding code word, and

generating a first dictionary including a pair of the respective detected phrase and the corresponding code word; and

executing a second generation process that includes

performing a block encrypting of the first dictionary to generate an encrypted dictionary information, and

generating a first file including a first region and multiple second regions to output the generated first file, the first region being configured to store the encoded information,

wherein a third region corresponding to the specific type among the second regions is configured to store the encrypted dictionary information.

2. The method according to claim 1 , further comprising:

executing a first determination process that includes determining whether or not the phrase included in the text information is already stored in a second dictionary,

wherein the first generation process is configured to extract, as the phrase of the specific type, a phrase determined as not being stored in the second dictionary and generate the encoded information and the first dictionary.

3. The method according to claim 1 ,

wherein the second generation process is configured to generate the first file further including a third dictionary in which a certain phrase other than the phrase of the specific type is associated with information obtained by encoding the certain phrase.

4. The method according to claim 1 ,

wherein the first generation process is configured to generate different first dictionaries in storage regions different for items of phrases of the specific type, and

wherein the second generation process is configured to use different encryption keys to encrypt the first dictionaries for the items to generate the encrypted dictionary information.

5. The method according to claim 1 , further comprising:

executing a second determination process that includes

determining, when a request to output the first file is received, whether or not the encoded information associated with the phrase of the specific type is to be decoded, based on an access right of a person who has requested the output, and

outputting text information including the phrase that is of the specific type and has been obtained by decoding the encoded information determined to be decoded.

6. The method according to claim 5 ,

wherein the second determination process is configured to output text information including a character string obtained by masking, based on a type associated with an item of the phrase of the specific type or the number of characters of the phrase of the specific type, the phrase that is of the specific type and associated with the encoded information determined to not be decoded.

7. The method according to claim 1 , further comprising:

executing a determination process that includes determining, based on an appearance frequency of the phrase of the specific type, either or both of a size of a storage region configured to store the encoded information and a size of the encoded information.

8. An apparatus for generating a file, the apparatus comprising:

a memory; and

a processor coupled to the memory and configured to

execute a reception process that includes receiving text information;

execute a first generation process that includes

obtaining one or more of detected phrases by detecting a phrase of a specific type from among the received text information,

generating, for a respective detected phrase, encoded information by converting the respective detected phrase into a corresponding code word, and

generating a first dictionary including a pair of the respective detected phrase and the corresponding code word;

execute a second generation process that includes

performing a block encrypting of the first dictionary to generate an encrypted dictionary information, and

generating a first file including a first region and multiple second regions to output the generated first file, the first region being configured to store the encoded information,

wherein a third region corresponding to the specific type among the second regions is configured to store the encrypted dictionary information.

9. The apparatus according to claim 8 ,

wherein the processor is configured to execute a first determination process that includes determining whether or not the phrase included in the text information is already stored in a second dictionary,

wherein the first generation process is configured to extract, as the phrase of the specific type, a phrase determined as not being stored in the second dictionary and generate the encoded information and the first dictionary.

10. The apparatus according to claim 8 ,

wherein the second generation process is configured to generate the first file further including a third dictionary in which a certain phrase other than the phrase of the specific type is associated with information obtained by encoding the certain phrase.

11. The apparatus according to claim 8 ,

wherein the first generation process is configured to generate different first dictionaries in storage regions different for items of phrases of the specific type, and

wherein the second generation process is configured to use different encryption keys to encrypt the first dictionaries for the items to generate the encrypted dictionary information.

12. The apparatus according to claim 8 ,

wherein the processor is further configured to

execute a second determination process that includes

determining, when a request to output the first file is received, whether or not the encoded information associated with the phrase of the specific type is to be decoded, based on an access right of a person who has requested the output, and

outputting text information including the phrase that is of the specific type and has been obtained by decoding the encoded information determined to be decoded.

13. The apparatus according to claim 12 ,

wherein the second determination process is configured to output text information including a character string obtained by masking, based on a type associated with an item of the phrase of the specific type or the number of characters of the phrase of the specific type, the phrase that is of the specific type and associated with the encoded information determined to not be decoded.

14. The apparatus according to claim 8 ,

wherein the processor is configured to execute a determination process that includes determining, based on an appearance frequency of the phrase of the specific type, either or both of a size of a storage region configured to store the encoded information and a size of the encoded information.

15. A non-transitory computer-readable storage medium for storing a program which causes a processor to perform processing for generating a file, the processing comprising:

executing a reception process that includes receiving text information;

executing a first generation process that includes

obtaining one or more of detected phrases by detecting a phrase of a specific type from among the received text information,

generating, for a respective detected phrase, encoded information by converting the respective detected phrase into a corresponding code word, and

generating a first dictionary including a pair of the respective detected phrase and the corresponding code word; and

executing a second generation process that includes

performing a block encrypting of the first dictionary to generate an encrypted dictionary information, and

generating a first file including a first region and multiple second regions to output the generated first file, the first region being configured to store the encoded information,

wherein a third region corresponding to the specific type among the second regions is configured to store the encrypted dictionary information.

16. The non-transitory computer-readable storage medium according to claim 15 ,

wherein the processing further comprises executing a first determination process that includes determining whether or not the phrase included in the text information is already stored in a second dictionary,

wherein the first generation process is configured to extract, as the phrase of the specific type, a phrase determined as not being stored in the second dictionary and generate the encoded information and the first dictionary.

17. The non-transitory computer-readable storage medium according to claim 15 ,

wherein the second generation process is configured to generate the first file further including a third dictionary in which a certain phrase other than the phrase of the specific type is associated with information obtained by encoding the certain phrase.

18. The non-transitory computer-readable storage medium according to claim 15 ,

wherein the first generation process is configured to generate different first dictionaries in storage regions different for items of phrases of the specific type, and

wherein the second generation process is configured to use different encryption keys to encrypt the first dictionaries for the items to generate the encrypted dictionary information.

19. The non-transitory computer-readable storage medium according to claim 15 ,

wherein the processing further comprises executing a second determination process that includes

determining, when a request to output the first file is received, whether or not the encoded information associated with the phrase of the specific type is to be decoded, based on an access right of a person who has requested the output, and

outputting text information including the phrase that is of the specific type and has been obtained by decoding the encoded information determined to be decoded.

20. The method according to claim 19 ,

wherein the second determination process is configured to output text information including a character string obtained by masking, based on a type associated with an item of the phrase of the specific type or the number of characters of the phrase of the specific type, the phrase that is of the specific type and associated with the encoded information determined to not be decoded.