Game data transfer between different platforms

1. A method comprising:

storing first user identification information of a user on a first platform, the first platform able to provide a game;

storing game data acquired by playing the game provided via the first platform with a first client device, the game data being stored in association with the first user identification information;

storing second user identification information of the user on a second platform;

generating an identification code by encoding identification data corresponding to the second user identification information;

outputting the identification code to a second client device that provides the game the second platform;

reading, with the first client device, the identification code output by the second client device;

generating link data based on the identification code read from the second client device, the link data associating the first user identification information stored on the first platform with the second user identification information stored on the second platform;

and

providing the game to the user via the second platform, based at least in part on the game data acquired in the game provided via the first platform, the game data being identified based on the second user identification information stored on the second platform and the link data.

2. The method according to claim 1 , wherein the identification code is an optically readable code.

3. The method according to claim 2 , wherein outputting identification code to a second client device comprises:

causing the identification code to be displayed on a display of the second client device.

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

transmitting a notification of completion to the second platform based on the first user identification information stored on the first platform being associated with the second user identification information stored on the second platform.

5. The method according to claim 4 , further comprising:

initiating the game on the second client device based on the notification of completion being received by the second platform.

6. The method according to claim 4 , wherein:

the identification code further includes a nonce, and

the notification of completion is generated to include the nonce.

7. The method according to claim 1 , wherein generating the identification code further comprises attaching an electronic signature to the encoded identification data, generating the link data comprises:

determining, using a public key, that the encoded identification data is valid; and

storing, based on the encoded identification data being determined to be valid, the first user identification information in association with the second user identification information.

8. The method according to claim 7 , wherein generating the identification code comprises encoding the identification data with a secret key corresponding to the public key.

9. The method according to claim 1 , wherein the identification code further includes expiration information indicating when the encoded identification code expires, generating the link data comprises:

determining that the identification code is unexpired; and

storing, based on the identification information being determined to be unexpired, the first user identification information in association with the second user identification information included in the identification code.

10. The method according to claim 1 , wherein the identification code further includes an issuer name indicating an issuer of the identification code, generating the link data comprises:

determining that the issuer name included in the identification code is valid; and

storing, based on the issuer name being determined to be valid, the first user identification information in association with the second user identification information.

11. The method according to claim 1 , wherein:

the game data on the first platform is identified based on the second user identification information and the link data, and

the game is provided to the second client device on the second platform using the game data.

12. The method according to claim 11 , wherein:

the identification code is generated on the second platform, and

the link data is generated on the first platform.

13. The method according to claim 1 , wherein:

the first platform identifies the user by the first user identification information and does not identify the user by the second user identification information, and

the second platform identifies the user by the second user identification information and does not identify the user by the first user identification information.

14. The method according to claim 1 , wherein the game data comprises at least one of game progress in the game provided by the first platform, game items acquired in the game provided by the first platform, game status in the game provided by the first platform, game points acquired in the game provided by the first platform, and game currency acquired in the game provided by the first platform.

15. A computer-readable tangible non-transitory storage medium comprising a program including executable instructions that, when executed, cause one or more computer processors to perform operations comprising:

storing first user identification information of a user on a first platform, the first platform able to provide a game;

storing game data acquired by playing the game provide via the first platform with a first client device, the game data being stored in association with the first user identification information;

storing second user identification information of the user on a second platform;

generating an identification code by encoding identification data corresponding to the second user identification information;

outputting the identification code to a second client device that provides the game via the second platform;

reading, with the first client device, the identification code output by the second client device;

generating link data based on the identification code read from the second client device, the link data associating the first user identification information stored on the first platform with the second user identification information stored on the second platform;

and

providing the game to the user via the second platform, based at least in part on the game data acquired in the game provided via the first platform, the game data being identified based on the second user identification information stored on the second platform and the link data.

16. A system comprising:

one or more processors; and

one or more storages configured to store first user identification information of a user on a first platform, second user identification information of the user on a second platform, and game data of the user in association with the first user identification information, the game data being acquired by playing a game provided via the first platform with a first client device, the first user identification information being used to identify the user on the first platform, and the second user identification information being used to identify the user on the second platform, wherein the one or more processors execute computer readable instructions to:

generate an identification code by encoding identification data corresponding to the second user identification information to generate an identification code;

output the identification code to a second client device that provides the game via the second platform;

read, with the first client device, the identification code output by the second client device;

generate link data based on the identification code read from the second client device, the link data associating the first user identification information stored on the first platform with the second user identification information stored on the second platform;

and

provide the game to the user via the second platform, based at least in part on the game data acquired in the game provided via the first platform, the game data being identified based on the second user identification information stored on the second platform and the link data.