Research Of Key Management In WLAN

With the high development of wirelss communication technology,WLAN has already become the typical applicantion of the network。WLAN has been resreached for only several years,with the flexible movement,fast and simple installment,the lower cost , robust expansibility and the convenience of maintenance and management,it developes quickly。But the research of it's security standard can't match with the development of the Wlan technology.The security problem is outstanding in key management.Without key management mechanism to generate and distribute key, As a consequence many IEEE 802.11 WLANs are operated in a completely insecure manner,representing an easy-to-attack target for even the most unskilled attackers, who happen to pass by near a building where an IEEE 802.11 WLAN is operated. First,This arcticle discuss the wlan security method from its appearance till now.The outstanding method is Wi-Fi standard technology,it adopt several methods to security wlan such as WEP,WPA,802.11X,802.11i.This arcticle describe this methods and their shortage are analyzed. Then,This arcticle introduce the technology of key management,describe the strategy of key management,the fator of the key management and the generation of key,The key distribution protocol is emphasized.(the public key distribution and the secret key distribution) And then under the key management problem of WEP and IEEE802.1X,this arcticle propose a key distribution based on the brocast key distribution frame,configure WEP with key distribution mechanism.This mechanism can generate , update and distribute the key dynamicly. Then under the problem of the key distribution based on the brocast key distribution frame,this arcticle propose a key distribution based on the multicast key distribution frame.With a few more storage and a few more bandwidth , this mechanism secure the key distribution frame,make the key distribution frame shorter. At the last,this arcticle introduce wlan key managemenet system,describe the key management mechanism of RSN,analyze the problem in RSN.The improved Diffie-Hellman arithmetic and the improved SAKA arithmetic are proposed to resolve the problem of the key generation and updation.