关键词: 无线局域网, 强安全网络, 扩展认证协议, 消息完整性码

Abstract: With the wide application of WLAN, wireless security has become a serious concern for an increasing number of people. As the basis of implementing a security system, key management is a problem to be solved urgently. To derivate a new Pairwise Transient Key (PTK), 4-Way Handshake needs to be carried out repeatedly between STA and AP, which worsens the overheads of STA. Aiming at this problem, a Key Server based Re-keying Scheme (KSRS) was proposed. This scheme adds a new level called Re-keying Level to the key hierarchy of 802.11i, which can implement centralized re-keying. Considering roaming character of STA and referring the centralized key management approach, this scheme uses an authentic entity called Key Server (KS) to distribute and refresh the keys, which can provide flexible operations for key management. A performance analysis on this scheme shows that it has lower overheads; thus it can be more suitable for mobility of STA.

Key words: WLAN, RSN, EAP, MIC