Apparatus and Method for Managing Content for Cloud Computing

1. A gateway connecting at least one user device to a plurality of cloud servers that provide different cloud services, the gateway comprising: a memory unit including an information table configured to store predefined Service Level Agreement (SLA) information having service usage fees for each cloud server; and a controller configured to select a cloud server from the plurality of cloud servers according to an ascending order of the service usage fees and to store content provided from the user device on the selected cloud server.

2. The gateway of claim 1 , wherein the information table is configured to store information relating to the service usage fees and a storage capacity with respect to each of the cloud servers.

3. The gateway of claim 2 , wherein when an available storage capacity of the selected cloud server is smaller than a size of the content, the controller is configured to select another cloud server.

4. The gateway of claim 1 , wherein the information table is generated and updated with a value that is either entered through the user device or provided from the cloud server.

5. A gateway connecting at least one user device to a plurality of cloud servers that provide different cloud services, the gateway comprising: a calculator configured to calculate response times for each of the cloud servers; and a selector configured to select a cloud server according to an ascending order of the response times from the cloud servers storing the requested content, to receive the requested content from the selected cloud server, and to provide the received content to the user device.

6. The gateway of claim 5 , further comprising: a response time table configured to store response times for the cloud servers, and a hash table configured to store information on cloud servers storing content on the content basis, wherein when the user device is configured to send a request for content, the selector is configured to select a cloud server from the cloud servers storing the requested content according to the ascending order of the response times, to receive a copy of the requested content from the selected cloud server, and to provide the copy of the content to the user device.

7. The gateway of claim 6 , wherein the calculator is configured to calculate the response times between sending a request for test content stored on the cloud servers and receiving the test content from the cloud servers, and to store the response times for the cloud servers on the response time table.

8. The gateway of claim 5 , further comprising: a verifier configured to verify cloud servers storing the content when the user device requests for content.

9. The gateway of claim 8 , wherein the verifier comprises: the hash table configured to store information of the response times between sending the a request for content and receiving a response to the request; a hash tree generator configured to generate a first hash tree using the content information; and a hash tree verifier configured to request and receive content information to and from a corresponding cloud server upon receiving a request for content, to generate a second hash tree using the received content information and content information of the hash tree verifier, and to verify the cloud server by comparing the first and second hash trees.

10. A method for operating a gateway connecting at least one user device to a plurality of cloud servers that provide different cloud services, the method comprising: storing a Service Level Agreement (SLA) information having service usage fees for each cloud server; selecting a cloud server from the cloud servers according to an ascending order of the service usage fees; and storing content provided from the user device, on the selected cloud server.

11. The method of claim 10 , wherein the selecting at least one of the cloud servers further comprises: selecting a next cloud according to the ascending order if an available storage of the selected cloud server is smaller than a size of the upload content.

12. The method of claim 10 , wherein the SLA information is generated and updated with a value which is entered through the user device or provided from the plurality of cloud servers.

13. A method for operating a gateway connecting at least one user device to a plurality of cloud servers that provide different cloud services, the method comprising: calculating a response time for each of the cloud servers; and when the user device requests for content, selecting a cloud server from the cloud servers storing the requested content according to an ascending order of the response times, receiving the requested content from the selected cloud server, and providing the received content to the user device.

14. The method of claim 13 , wherein calculating a response time for each of the cloud servers comprises: requesting for a test content to the cloud servers at a preset interval; and measuring the response times until the test content is received from the cloud servers.

15. The method of claim 13 , further comprising: when the user device requests to view content, verifying cloud servers storing the requested content.

16. The method of claim 15 , further comprising: generating a first hash tree using content information; requesting and receiving content information to and from cloud servers storing content when the user device requests for the content; generating a second hash tree using the received content information and content information stored therein, and verifying cloud servers by comparing the hash trees; and selecting a verified cloud server from the verified cloud servers storing the requested content according to the ascending order of the response times.