Abstract: A data access control method includes requesting, by the data owner unit, the generation of a data encryption key (DEK) from the manager unit, generating, by the manager unit, the DEK, generating, by the manager unit, the result of the Ciphertext Policy-Attribute Based Encryption (CP-ABE) of the DEK and a secret key used to decrypt the result of the CP-ABE encryption, and then responding, by the manager unit, to the data owner unit, obtaining, by the data owner unit, the DEK by performing the CP-ABE decryption of the result of the CP-ABE encryption using the secret key, encrypting, by the data owner unit, data with the obtained DEK, and uploading, by the data owner unit, the encrypted data and DEK information to the cloud.

Abstract: An apparatus and method for providing a security keypad are provided. The apparatus for providing a security keypad includes a coordinate generation unit, a keypad output unit, and a key value processing unit. The coordinate generation unit computes a displacement by which a security keypad is to be shifted, and rearranges at least some of keys included in the security keypad by shifting the at least some keys so that the central axis of the security keypad is translated by the displacement. The keypad output unit displays the rearranged security keypad to a user. The key value processing unit processes key values in response to the user's input to the rearranged security keypad, and transfers the processed key values to an application for which the rearranged, security keypad is used.

Abstract: An apparatus and method for protecting user data are disclosed herein. The apparatus for protecting user data includes a network filter, a user authentication unit, a message relay unit, and a key management unit. The network filter filters traffic between a user and a cloud server. The user authentication unit registers and authenticates the user. The message relay unit relays a message and data included in the traffic between the user and the cloud server. The key management unit generates and manages a key required to encrypt the data.

Abstract: A data access control method includes requesting, by the data owner unit, the generation of a data encryption key (DEK) from the manager unit, generating, by the manager unit, the DEK, generating, by the manager unit, the result of the Ciphertext Policy-Attribute Based Encryption (CP-ABE) of the DEK and a secret key used to decrypt the result of the CP-ABE encryption, and then responding, by the manager unit, to the data owner unit, obtaining, by the data owner unit, the DEK by performing the CP-ABE decryption of the result of the CP-ABE encryption using the secret key, encrypting, by the data owner unit, data with the obtained DEK, and uploading, by the data owner unit, the encrypted data and DEK information to the cloud.

Abstract: An apparatus and method for encryption in a virtualized environment using an auxiliary medium. The apparatus for encryption in a virtualized environment using an auxiliary medium includes a hypervisor unit for acquiring data for encryption from an auxiliary medium, and encrypting and providing protection target data of an application program using the data for encryption in response to an encryption request from the application program. A hypercall unit provides a virtualization interface between the application program and the hypervisor unit.

Abstract: An apparatus and method for providing a security keypad are provided. The apparatus for providing a security keypad includes a coordinate generation unit, a keypad output unit, and a key value processing unit. The coordinate generation unit computes a displacement by which a security keypad is to be shifted, and rearranges at least some of keys included in the security keypad by shifting the at least some keys so that the central axis of the security keypad is translated by the displacement. The keypad output unit displays the rearranged security keypad to a user. The key value processing unit processes key values in response to the user's input to the rearranged security keypad, and transfers the processed key values to an application for which the rearranged, security keypad is used.

Abstract: An apparatus and method for encryption in a virtualized environment using an auxiliary medium. The apparatus for encryption in a virtualized environment using an auxiliary medium includes a hypervisor unit for acquiring data for encryption from an auxiliary medium, and encrypting and providing protection target data of an application program using the data for encryption in response to an encryption request from the application program. A hypercall unit provides a virtualization interface between the application program and the hypervisor unit.