Patent ID: 8924732

Claim:
A method of cipher communication for management frame performed by a station in a wireless local area network system, the method comprising: obtaining a first pseudonoise (PN) code sequence for a plaintext Medium Access Control (MAC) protocol data unit (MPDU); constructing an additional authentication data (AAD) by using fields in a header of the plaintext MPDU; constructing a Nonce from the PN code sequence, an Address 2 field in the header of the plaintext MPDU and a Priority field in the header of the plaintext MPDU; generating a counter mode (CTR) with cipher block chaining (CBC)-MAC protocol (CCMP) header including a second PN code sequence and a key identifier; generating encrypted data and message integrity code (MIC) by using a temporal key, the AAD, and the Nonce; generating an encrypted MPDU by combining the header of the plaintext MPDU, the CCMP header, the encrypted data and the MIC; and transmitting the encrypted MPDU to a peer station; wherein the plaintext MPDU is a management frame including a sequence number field, the sequence number field including an access category field indicating a category of data included in the plaintext MPDU, and wherein the Nonce includes a priority field set to a value in the access category field of the sequence number field.