Authorship determining method, computer, and program

1 . An authorship determining method for determining authorship of an artwork by using a computer, comprising:

receiving first pre-integration data including a plurality of partial artworks, wherein the first pre-integration data is pre-rasterization data different from the artwork which is post-rasterization data;

calculating a first hash value as a hash value of the first pre-integration data;

generating a first creation certificate including the first hash value;

receiving second pre-integration data;

determining the authorship of the artwork based on whether the first hash value obtained from the first creation certificate matches a second hash value calculated from the second pre-integration data.

2 . The authorship determining method according to claim 1 , comprising:

receiving the first creation certificate possessed by a creator of the artwork, and obtaining the first hash value from the received first creation certificate, and

obtaining the first pre-integration data possessed by the creator as the second pre-integration data, and calculating the second hash value of the obtained first pre-integration data.

3 . The authorship determining method according to claim 1 , wherein

the artwork is an artwork embedded with a predetermined watermark, and

the authorship determining method comprises:

determining the authorship of the artwork by determining whether or not the predetermined watermark can be obtained from the artwork.

4 . The authorship determining method according to claim 3 , wherein

the predetermined watermark is a watermark indicating a project identifier identifying a project generated according to an instruction of a creator and related to creation of the artwork, and

the authorship determining method comprises:

associating the project identifier and the first creation certificate with each other.

5 . The authorship determining method according to claim 2 ,

comprising:

receiving the first creation certificate encrypted by a private key of the creator,

obtaining a public key of the creator on a basis of information indicating the creator obtained on a basis of the project identifier indicated by the predetermined watermark obtained from the artwork, and

determining the authorship of the artwork by determining whether or not the first creation certificate can be decrypted by using the obtained public key of the creator.

6 . The authorship determining method according to claim 1 , wherein

the artwork includes a project identifier that identifies a project generated according to an instruction of a creator and related to creation of the artwork, and

the authorship determining method comprises:

attempting to obtain the project identifier from the artwork, and

determining the authorship of the artwork by determining whether or not the project identifier can be obtained from the artwork.

7 . The authorship determining method according to claim 1 , comprising:

generating creation certification information by encrypting the first hash value by using a first private key, wherein

the first creation certificate includes the creation certification information.

8 . The authorship determining method according to claim 7 , comprising:

determining the authorship of the artwork by determining whether or not the creation certification information included in the first creation certificate can be decrypted by using a first public key corresponding to the first private key.

9 . The authorship determining method according to claim 1 , comprising:

searching for an image online by using the artwork, wherein

the first creation certificate includes information indicating a result of the search for the image.

10 . The authorship determining method according to claim 1 , comprising:

receiving a license application from a user other than a creator of the artwork, and

issuing, to the user, a license certificate including license certification information including information indicating a licensee in response to the license application, wherein

license information in the license certification information is encrypted by using a first private key.

11 . The authorship determining method according to claim 10 , comprising:

receiving the license certificate possessed by the user,

obtaining the license certification information from the received license certificate by decrypting the license certification information included in the received license certificate by using a first public key corresponding to the first private key, and

determining that the user is a licensee of the artwork when the license certification information can be decrypted by using the first public key.

12 . The authorship determining method according to claim 11 , wherein

the artwork is an artwork embedded with a predetermined watermark, and

the authorship determining method comprises:

attempting to obtain the predetermined watermark embedded in the artwork possessed by the user, and

determining that the user is a licensee of the artwork when the predetermined watermark can be obtained from the artwork.

13 . The authorship determining method according to claim 12 , wherein

the predetermined watermark is a watermark indicating a project identifier that identifies a project generated according to an instruction of the creator of the artwork and related to creation of the artwork, and

the authorship determining method comprises:

associating the project identifier and the license certificate with each other.

14 . The authorship determining method according to claim 13 , comprising:

receiving the license certificate encrypted by a private key of the user,

obtaining the license certificate on a basis of the project identifier indicated by the predetermined watermark obtained from the artwork,

obtaining the license certification information from the obtained license certificate, and obtaining a public key of the user indicated by the license certification information,

attempting to decrypt the received license certificate by using the obtained public key of the user, and

determining that the user is a licensee of the artwork when the license certificate can be decrypted by the public key of the user.

15 . The authorship determining method according to claim 1 , comprising:

searching for an image online by using an artwork not embedded with a predetermined watermark, wherein

the first creation certificate includes a result of the search for the image.

16 . A computer used to determine authorship of an artwork, the computer comprising:

memory including computer-executable instructions; and

a processor configured to:

receive first pre-integration data including a plurality of partial artworks, wherein the first pre-integration data is pre-rasterization data different from the artwork which is post-rasterization data;

calculate a first hash value as a hash value of the first pre-integration data;

generate a first creation certificate including the first hash value;

receive second pre-integration data; and

determine the authorship of the artwork based on whether the first hash value obtained from the first creation certificate matches a second hash value calculated from the second pre-integration data.

17 . A non-transitory computer-readable medium including a program for causing a computer to execute processing of certifying authorship of an artwork, wherein the processing comprises:

receiving first pre-integration data including a plurality of partial artworks, wherein the first pre-integration data is pre-rasterization data different from the artwork which is post-rasterization data;

calculating a first hash value as a hash value of the first pre-integration data;

generating a first creation certificate including the first hash value;

receive second pre-integration data; and

determining the authorship of the artwork based on whether the first hash value obtained from the first creation certificate matches a second hash value calculated from the second pre-integration data.