MAC security entity for link security entity and transmitting and receiving method therefor

An apparatus of a MAC security reception unit comprising:

• a frame classifier determining based on the LLID value of a frame whether or not a security function is applied to the frame, determining based on the type value of the frame whether the frame is an encrypted frame or a non-encrypted plaintext frame, and processing a denial of service (DoS) attack frame based on a user-defined parameter value in relation to each frame;
• a parameter verification unit transmitting a parameter set value used in the decryption and authentication of the frame;
• a retransmission attack processing unit, if the frame corresponds to a retransmission attack frame, removing the frame based on the association number (AN) flag value of the frame;
• and
• a bypass unit delaying the plaintext frame so that a processing time taken for decrypting the encrypted frame is the same as a time of processing the plaintext frame.

A frame transmission method in a MAC security transmission apparatus comprising:

• determining based on the LLID value of a frame whether or not a security function is to be applied;
• delaying a no-security-function frame so that a processing time for converting a security-function-applied frame into an encrypted frame is the same as a processing time for the no-security-function frame;
• and
• in relation to each of the LLIDs, transmitting a parameter set value, including a security-function-application setting signal used in the encryption, decryption and authentication of the frame, a frame decryption signal, an encryption mode selection signal, and an authentication intensity adjustment signal.

A frame reception method in a MAC security reception apparatus comprising:

• based on the LLID value of a frame, determining whether or not a security function is applied to the frame;
• determining based on the type value of the frame whether the frame is an encrypted frame or non-encrypted plaintext frame, and processing a DoS attack frame based on a user-defined parameter value in relation to each frame;
• transmitting a parameter set value used in the decryption and authentication of the frame;
• based on the AN flag value of the frame, if the frame corresponds to a retransmission attack frame, removing the frame;
• and
• delaying the plaintext frame so that a processing time taken for decrypting the encrypted frame is the same as a time for processing the plaintext frame.

A frame transmission and reception method in a MAC security apparatus comprising:

• classifying a frame and determining whether or not a security function is applied, based on the LLID value and the type of the frame;
• in relation to each of the LLIDs, transmitting a parameter set value, comprising a security-function-application setting signal used in the encryption, decryption and authentication of the frame, a frame decryption signal, an encryption mode selection signal, and an authentication intensity adjustment signal;
• delaying the no-security-function frame so that a processing time for converting the security-function-applied frame into an encrypted frame is the same as a time for processing the no-security-function frame;
• authentication decrypting or authenticating the frame;
• based on the LLID value, determining whether or not an encryption mode is set in the frame;
• determining based on the type value of the frame whether the frame is an encrypted frame or a non-encrypted plaintext frame, and processing a DoS attack frame in relation to each frame based on the frame type value;
• delaying the plaintext frame so that a processing time taken for decrypting the encrypted frame is the same as a time for processing the plaintext frame;
• and
• transmitting a second parameter set value used in the authentication and decryption of the frame.