密碼學報告 Wired Equivalent Privacy Algorithm, WEP 有線等效保密演算法

Wired Equivalent Privacy Algorithm, WEPPresentChang Yung-Chang

(Open System)(Shared Key)WEPWEPOutline

Ad-Hoc LANInfrastructured wireless LAN

(Open System)MAC

(Open System)(a)(b)

Authentication Algorithm Number=0Authentication Transaction SequenceNumber=1Status Code

Authentication Algorithm Number=0Authentication Transaction SequenceNumber=2Status Code=

(Shared Key) RADIUS (Challenge/Response)

(Shared Key)

(Shared Key)(a)(b)

(Shared Key)(c)(d)

WEP

WEPEk(P)=CDk(C)=Dk(Ek(P))=P

WEPWEP

WEPWEPMPDU

WEPWEP

() () ? ?Identity assertionAuthentication frame13-13(a)SA(Station ID) 13-13(b)(WEPOFF) Identity assertionAuthentication frame13-13(a)SA(Station ID) 13-13(b)(WEPOFF) (Shared Key) ()IEEE 802.11WEP(Authentication frame)13-14(a)(Identity assertion) SA(Station ID)(result)()WEP128(Challenge text) 12-14(b)(WEP=OFF) 13-14(c)(WEP=ON) 13-14(d)(WEP=OFF) (Authentication frame)13-14(a)(Identity assertion) SA(Station ID)(result)()WEP128(Challenge text) 12-14(b)(WEP=OFF) 13-14(c)(WEP=ON) 13-14(d)(WEP=OFF)

(brute-force)WEP(Initialization Vector, IV) WEP(self-synchronization)(data-link level)WEPWEP() WEP802.11WEP802.11WEP() WEP