Ib hom kev ua haujlwm piav qhia yuav ua li cas rov siv lub cipher ib zaug ua haujlwm kom ruaj ntseg hloov pauv cov ntaub ntawv loj dua li qhov thaiv. Feem ntau cov qauv yuav tsum muaj qhov tshwj xeeb binary ib ntus, feem ntau hu ua qhov pib vector (IV), rau txhua qhov kev ua haujlwm encryption.
Vim li cas cov qauv kev ua haujlwm xav tau rau thaiv ciphers?
Block Cipher Hom Kev Ua Haujlwm. Ib qho ntawm cov teeb meem tseem ceeb nrog cov ntawv ciphers yog qhov lawv tsuas yog tso cai rau koj los encrypt cov lus tib yam li lawv qhov ntev thaiv. Yog tias koj siv TEA, uas muaj qhov thaiv qhov loj ntawm 64 me ntsis, txhawm rau txhawm rau xa cov lus 65 me ntsis, koj xav tau txoj hauv kev los txheeb xyuas qhov thaiv thib ob yuav tsum tau encrypted li cas.
Dab tsi yog qhov txiaj ntsig loj tshaj ntawm CBC hom kev ua haujlwm?
Qhov zoo thiab qhov tsis zoo ntawm kev siv CBC hom
qhov zoo tshaj plaws CBC muaj tshaj ECB yog tias, nrog CBC hom, zoo tib yam blocks tsis muaj tib lub cipher. Qhov no yog vim qhov pib vector ntxiv ib qho random rau txhua qhov thaiv; yog li ntawd, yog vim li cas tib blocks nyob rau hauv txawv txoj hauj lwm yuav muaj sib txawv ciphers.
Kev ua haujlwm txawv li cas?
Kev daws teeb meem: tsib hom qauv ntawm Kev Ua Haujlwm: Phau Ntawv Hluav Taws Xob (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), Cov Lus Qhia Tawm (OFB), thiab Counter (CTR).
Vim li cas ECB tsis ruaj ntseg?
Qhov laj thawj tseem ceeb tsis siv ECB hom encryption yog tias nws tsis muaj kev nyab xeeb - uas yog, tsuas yog saib xyuas ECB-encrypted ciphertext tuaj yeem xau cov ntaub ntawv hais txog cov ntawv dawb(txawm tias dhau nws qhov ntev, uas txhua qhov txheej txheem encryption lees txais arbitrarily ntev plaintexts yuav xau rau qee qhov).
