Abstract: A method for using contents, a method for sharing contents, and a device based on security level are disclosed. A method for using contents based on security level creates a device security level according to the number of device identification elements, receives contents, and if the device security level is found to be a minimum allowed device security level for using the contents, uses the contents. Therefore, a device that does not satisfy the conditions required for using contents cannot use the contents, whereby security is reinforced.

Abstract: A secure signing method, a secure authentication method, and an IPTV system are disclosed. The secure signing method includes preparing digital signature header fields and setting an attribute, calculating a hash digest of content using a hashing algorithm, storing the calculated hash value in a message digest field of the digital signature header, encrypting the message digest using a secret key and inserting the encrypted message digest in a signature field of the digital signature header, and associating the digital signature header with the content by prefixing the digital signature header to the content.

Abstract: A method and system for secure communication is provided. The method for secure communication with devices includes: obtaining a parameter for protecting a content; authenticating each other by exchanging a certificate with the device; and exchanging a key with the device using a key authenticated through the certificate to establish a secure authenticated channel with the device. Accordingly, it is possible to establish the secure authenticated channel and perform secure communication by computing a secure authenticated channel key.

Abstract: Disclosed is a method of sharing content. According to the content sharing method, content is received from a service provider using a receive device. A content protection solution supported in a target device is detected. The content is converted so that it is compatible with a content protection solution supported in any one of the target device and the receive device on the basis of the detected content protection solution. The receive device can include a security solution level, indicating a security characteristic of the receive device, in a certificate of the receive device. Accordingly, content transmitted from a service provider using a receive device can be shared efficiently by redistributing the content in such a way as to be compatible with a security solution of a home device.

Abstract: Disclosed are a data processing method and an IPTV receiving device. The data processing method includes a data processing method of a DRM component of an IPTV receiving device. A packet to be decrypted and its associated information are received from a server. The packet is decrypted by performing any one of its own decryption and decryption using external hardware. In the case in which the its own decryption is performed, the packet is received and decrypted using internal software. In the case in which the decryption using the external hardware is performed, an external trusted hardware component within the IPTV receiving device is exchanged with a key.

Abstract: A method and system for secure communication is provided. The method for secure communication with devices includes: obtaining a parameter for protecting a content; authenticating each other by exchanging a certificate with the device; and exchanging a key with the device using a key authenticated through the certificate to establish a secure authenticated channel with the device. Accordingly, it is possible to establish the secure authenticated channel and perform secure communication by computing a secure authenticated channel key.

Abstract: A secure signing method, a secure authentication method, and an IPTV system are disclosed. The secure signing method includes preparing digital signature header fields and setting an attribute, calculating a hash digest of content using a hashing algorithm, storing the calculated hash value in a message digest field of the digital signature header, encrypting the message digest using a secret key and inserting the encrypted message digest in a signature field of the digital signature header, and associating the digital signature header with the content by prefixing the digital signature header to the content.

Abstract: A method for using contents, a method for sharing contents, and a device based on security level are disclosed. A method for using contents based on security level creates a device security level according to the number of device identification elements, receives contents, and if the device security level is found to be a minimum allowed device security level for using the contents, uses the contents. Therefore, a device that does not satisfy the conditions required for using contents cannot use the contents, whereby security is reinforced.

Abstract: A method and system for secure communication is provided. The method for secure communication with devices includes: obtaining a parameter for protecting a content; authenticating each other by exchanging a certificate with the device; and exchanging a key with the device using a key authenticated through the certificate to establish a secure authenticated channel with the device. Accordingly, it is possible to establish the secure authenticated channel and perform secure communication by computing a secure authenticated channel key.