AES vs TKIP
Thaum sib txuas lus tshaj qhov nruab nrab tsis ntseeg xws li wireless network, nws tseem ceeb heev los tiv thaiv cov ntaub ntawv. Cryptography (encryption) plays lub luag haujlwm tseem ceeb hauv qhov no. Cov khoom siv Wi-Fi niaj hnub no feem ntau tuaj yeem siv WPA lossis WPA2 wireless kev ruaj ntseg raws tu qauv. Tus neeg siv tuaj yeem siv TKIP (Temporal Key Integrity Protocol) encryption raws tu qauv nrog WPA thiab AES (Advanced Encryption Standard) encryption standard raws li CCMP encryption raws tu qauv nrog WPA2.
AES yog dab tsi?
AES belongs rau tsev neeg ntawm symmetric-key encryption tus qauv. AES tau tsim nyob rau xyoo 2001 los ntawm NIST (National Institute of Standards and Technology). Tom qab ib xyoos nkaus xwb, tsoomfwv Meskas tau xaiv nws los ua tsoomfwv tus qauv. Nws tau pib hu ua Rijndael, uas yog ib lo lus ntawm ob tus neeg tsim khoom Dutch Joan Daemen thiab Vincent Rijmen. NSA (Lub Chaw Saib Xyuas Kev Ruaj Ntseg Hauv Tebchaws) siv AES rau kev ua haujlwm zais cia sab saum toj. Qhov tseeb AES yog NSA thawj zaug uas pej xeem thiab qhib cipher. AES-128, AES-192 thiab AES-256 yog peb qhov thaiv ciphers uas tsim cov qauv no. Tag nrho peb muaj qhov loj me ntawm 128-ntsis thiab muaj 128-ntsis, 192-ntsis thiab 256-ntsis qhov tseem ceeb ntawm qhov ntau thiab tsawg. Cov txheej txheem no yog ib qho ntawm cov ciphers uas tau siv dav tshaj plaws. AES yog tus ua tiav rau DES (Data Encryption Standard).
AES lees txais los ua tus qauv encryption ruaj ntseg heev. Nws tau ua tiav kev tawm tsam tsuas yog ob peb zaug xwb, tab sis lawv yog txhua qhov kev tawm tsam sab nraud ntawm qee qhov kev siv ntawm AES. Vim nws txoj kev ruaj ntseg thiab kev ntseeg siab, NSA siv nws los tiv thaiv cov ntaub ntawv tsis raug cais thiab cais tawm ntawm Tsoomfwv Meskas (NSA tshaj tawm qhov no hauv 2003).
TKIP yog dab tsi?
TKIP (Temporal Key Integrity Protocol) yog kev ruaj ntseg wireless raws tu qauv. Nws yog siv hauv IEEE 802.11 wireless networks. IEEE 802.11i pab pawg ua haujlwm thiab Wi-Fi Alliance sib koom ua ke tsim TKIP txhawm rau hloov WEP, uas tseem yuav ua haujlwm ntawm kev xa tawm WEP tshaj kho vajtse. TKIP yog qhov tshwm sim ncaj qha ntawm kev tawg ntawm WEP uas ua rau Wi-nkaus tes hauj lwm ua yam tsis muaj tus qauv txuas txheej txheej kev ruaj ntseg raws tu qauv. Tam sim no, TKIP tau pom zoo raws li WPA2 (Wi-Fi Protection Access version 2). TKIP muab qhov tseem ceeb sib xyaw (sib txuas cov hauv paus zais cia nrog lub cim pib vector) raws li kev txhim kho WEP. Nws kuj tseem tiv thaiv kev tawm tsam rov ua dua los ntawm kev siv lub txee ua ntu zus thiab tsis lees txais cov ntawv txiav txim tawm. Tsis tas li ntawd, TKIP siv 64-ntsis MIC (Kev Tshawb Fawb Kev Ncaj Ncees), rau kev tiv thaiv kev lees txais cov pob ntawv forged. TKIP yuav tsum siv RC4 raws li nws tus lej cim vim nws yuav tsum tau ua kom paub tseeb tias nws yuav khiav ntawm WEP cov cuab yeej cuab tam qub. Txawm hais tias, TKIP tiv thaiv ntau qhov kev tawm tsam uas WEP muaj kev cuam tshuam rau (xws li kev tawm tsam rov qab), nws tseem muaj kev cuam tshuam rau qee qhov kev tawm tsam me xws li Beck-Tews nres thiab Ohigashi-Morii nres.
Qhov txawv ntawm AES thiab TKIP yog dab tsi?
AES yog tus qauv encryption, thaum TKIP yog tus txheej txheem encryption. Txawm li cas los xij, AES raws li CCMP qee zaum hu ua AES (tej zaum ua rau qee qhov tsis meej pem). TKIP yog tus txheej txheem encryption siv hauv WPA, thaum WPA2 (uas hloov WPA) siv (AES raws) CCMP ua tus txheej txheem encryption. AES yog tus ua tiav rau DES, qhov TKIP tau tsim los hloov WEP. Kev siv tsawg heev ntawm AES muaj kev cuam tshuam rau sab channel tawm tsam, thaum TKIP muaj kev cuam tshuam rau ob peb lwm qhov kev tawm tsam nqaim. Zuag qhia tag nrho, CCMP suav hais tias muaj kev nyab xeeb dua li TKIP.
