Apparatus, method and system for providing a broadcasting service in a digital broadcasting system with a single frequency network

A method for providing a broadcasting service through a defined frequency in a digital broadcasting system, comprising the steps of:

• encrypting broadcasting service data, generating a private key and a public key into which predetermined encryption keys are divided to decrypt the encrypted broadcasting service data, and transmitting the encrypted broadcasting service data and the encryption keys to broadcasting transmitters for transmitting the private key and/or the public key;
• transmitting the encrypted broadcasting service data and the private key from the broadcasting transmitters using the defined frequency;
• and
• further transmitting the public key from at least one of the broadcasting transmitters.

A reception apparatus for receiving encrypted broadcasting service data from at least one broadcasting transmitter in a digital broadcasting system with the at least one broadcasting transmitter for transmitting the encrypted broadcasting service data through a defined frequency, comprising:

• a receiver for receiving a public key and/or a private key for decrypting broadcasting service data from a frame of the broadcasting service data;
• a decryption key generator for receiving the public key and/or a private key and generating at least one Control Word (CW) for decrypting the broadcasting service data using the public key and/or the private key;
• and
• control means for controlling decryption key generator to generate the at least one CW and decrypting the broadcasting service data with the at least one generated CW according to a designated condition.

A reception method for receiving encrypted broadcasting service data from at least one broadcasting transmitter in a digital broadcasting system with the at least one broadcasting transmitter for transmitting the encrypted broadcasting service data through a defined frequency, comprising the steps of:

• receiving a public key and/or a private key for decrypting the broadcasting service data from a frame of the broadcasting service data;
• generating at least one Control Word (CW) for decrypting the broadcasting service data using the public key and/or the private key;
• and
• decrypting the broadcasting service data with the at least one generated CW according to a designated condition.