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Wimax technology for broadband wireless access 2007 p1

Năm nguyên tắc này sẽ được xem xét điều đó. Không ai có thể dự đoán một cách chắc chắn những hành động của tổ chức đối thủ cạnh tranh trong tương lai, chỉ đạo của nền kinh tế quốc dân sẽ mất vào năm tới, hoặc những tiến bộ công nghệ sẽ trở thành thương mại trong | Security 249 Sequence Number in the HMAC Tuple is equal to the AK Sequence Number of the AK from which the HMAC_KEY_x was derived. Calculation of the keyed hash in the HMAC-Digest attribute and the HMAC Tuple uses the HMAC 44 45 with the cryptographic secure hash algorithm SHA-1 FIPS 180-1 49 . This authentication method is often known as HMAC-SHA1. The digest must be calculated over the entire MAC management message with the exception of the HMAC-Digest and HMAC Tuple attributes. 802.16e added the possibility of using a Cipher-based Message Authentication Code CMAC RFC 4493 46 as an alternative to the HMAC. For the CMAC AES block ciphering is used for MAC calculations AES-CMAC . The digest is calculated over an entire MAC management message with the exception of the HMAC-Digest or HMAC Tuple attributes. 15.4.1 Message Authentication Keys The authentication keys used for the calculation of HMAC keyed hash included in some MAC management messages see above are the downlink authentication key HMAC_KEY_D used for authenticating messages in the downlink direction the uplink authentication key HMAC_KEY_U used for authenticating messages in the uplink direction. As for PKMv1 the PKMv2 MAC message for the uplink is C HMAC_KEY_U and the MAC message for the downlink is C HMAC_KEY_D. hMaC_KEY_D and HMAC_KEY_U are derived from the AK as mentioned in Section 15.3 above. The HMAC CMAC KEK derivation from the AK is illustrated in Figure 15.14. CMAC_KEY_U 128 bits CMAC_KEY_D 128 bits KEK 128 bits HMAC_KEY_U 160 bits HMAC_KEY_D 160 bits KEK 128 bits Figure 15.14 HMAC CMAC KEK derivation from the AK. Based on Reference 2 . 250 WiMAX Technology for Broadband Wireless Access The BS uses HMAC_KEY_D and HMAC_KEY_U for the following Verify the HMAC-Digest attributes in Key Request MAC management messages received from that SS using HMAC_KEY_U. Calculate using HMAC_KEY_D the HMAC-Digest attributes it writes into Key Reply Key Reject and TEK Invalid MAC management messages sent to that .