Isiseko seCryptography

I-Cryptography ibhekisa kwinkqubo yokufihla ulwazi ngokuguqula isicatshulwa esifundekayo sibe sisicatshulwa esingafundekiyo usebenzisa uhlobo oluthile lwesitshixo okanye i-encryption algorithm.

Ulwazi olukhuselweyo kusetyenziswa ukufihla kubandakanya ii-imeyile, iifayile kunye nolunye ulwazi olunobuzaza.

Injongo yokubhala ngokufihlakeleyo kukuqinisekisa ukuba ulwazi olufihliweyo lugcina imfihlo, ukuthembeka, ubunyani, kunye nokungala.




Iindidi ze-Cryptography

Ukubhala ngeendlela ezimbini:

  • Ukubethela okulinganayo isebenzisa isitshixo esinye ukuguqulela ngokufihlakeleyo okanye ngokufihlisa ulwazi oluthunyelwe / olufunyenweyo.
  • Ukubhalwa kwe-Asymmetric isebenzisa izitshixo ezahlukeneyo ukubethela kunye nokubethela ulwazi oluthunyelwe / olufunyenweyo.


IChipher

I-Cipher ibhekisa kwi-algorithm esetyenziselwa ukubethela kunye nokuseta.


Iindidi zeChipher zezi:



Iimpawu zokuqala

  • Ukufakwa endaweni yoko licher apho isicatshulwa esicacileyo sifakwa endaweni yombhalo ocacileyo.
  • Utshintsho cipher yi-cipher apho okubhaliweyo okucacileyo kuhlelwa kwakhona ukwenza umbhalo-ngqangi.

I-cipher yanamhlanje


  • Iimpawu eziphambili ezisekwe:



    • Isimethrikhi isitshixo sealgorithm yialgorithm esebenzisa isitshixo esinye sokubethela kunye nokuseta

    • I-asymmetric key algorithm yi-algorithm esebenzisa izitshixo ezibini zokubethela kunye nokuseta


  • Igalelo elisekwe kufakelo:



    • I-block cipher sisixhobo esisebenza kwiibhloko zedatha emiselweyo kusetyenziswa isitshixo semetri

    • Ukusasazeka kwe-cipher sisixhobo esisebenza kancinci ngexesha elinye usebenzisa isitshixo semetri



Ubuchule bokubhala ngokufihlakeleyo

OF

I-DES yimigangatho yokubethela idatha esebenzisa ukubethela okungqinelanayo. Isitshixo semfihlo esisetyenziselwa ukubethela kunye nokuseta ngokuchanekileyo sinama-bits angama-64, aphuma kuwo angama-56 amasuntswana aveliswa ngokungacwangciswanga kwaye iibits ezisibhozo ezisetyenzisiweyo zisetyenziselwa ukukhangela impazamo.


I-AES

I-AES yi-symmetric-key algorithm eyenza ukusebenza okufanayo amaxesha amaninzi. Isebenzisa ibhloko yesayizi emiselweyo engama-128 kunye namaqhosha obungakanani obuthathu: i-128, 192, kunye ne-256 bits.

RC4, RC5, RC6

RC4 ubude beguquguqukayo yesitshixo esisebenza ngexesha elinye kwaye sisebenzisa iimvumelwano ezingahleliwe. Yeqela le symmetric-key stream ciphers.

RC5 yi-algorithm eyenziwe ngokomgaqo enobungakanani bebhloko eguquguqukayo, ubungakanani besitshixo esiguqukayo, kunye nenani eliguqukayo leerandi. Ubungakanani bebhloko bunokuba yenye yezi zinto zintathu: 32, 64, kunye ne-128 bits. Ubungakanani obuphambili bunokuba phakathi kwe-0 kunye ne-2,040 bits. Inani lemijikelezo lingaba phakathi kuka-0 no-255.

RC6 ivela kwi-RC5 kwaye inezinto ezimbini ezongezelelweyo: isebenzisa amanani aphindaphindiweyo kunye neerejista ezi-4-bit (i-RC5 isebenzisa iirejista ezi-2-bit).


Zimbini

I-algorithm ye-Twofish yi-block cipher esebenzisa iibhloko ze-128-bit kunye nesitshixo esinye sokubethela kunye nokuseta. Ubungakanani besitshixo bunokuvela kwi-0 kuye kwi-256 bits.

DSA

I-DSA yi-asymmetric algorithm esebenzisa zombini izitshixo zabucala nezikawonke-wonke. Isitshixo sangasese sixelela ukuba ngubani otyikitye umyalezo, kwaye isitshixo soluntu siqinisekisa utyikityo lwedijithali. Kuthungelwano lomyalezo phakathi kwamacandelo amabini, icandelo ngalinye lenza isitshixo esidlangalaleni nakwabucala.

RSA

I-RSA isebenzisa i-modular arithmetic kunye nenani leenethiyori zenani lokwenza amanani kusetyenziswa amanani amabini amakhulu. Iqwalaselwa njengomgangatho wokubhala ngokufihlakeleyo kwaye ngenxa yoko isetyenziswa kwizicelo ezahlukeneyo. I-RSA isebenzisa izitshixo zabucala nezasesidlangalaleni kwinkqubo yokubethela kunye nokuseta.

UDiffie-Hellman

I-algorithm ye-Diffie-Hellman isetyenziselwa ukwenza isitshixo ekwabelwana ngaso phakathi kwamacandelo amabini kwisiteshi esingakhuselekanga. Ivumela amaqela amabini ukuba enze isitshixo sokubethela kwaye emva koko abethele ukugcwala kwabo ngeso sitshixo.


Umyalezo wokuGaya

Umsebenzi wokwetyiswa kwemiyalezo, okanye indlela yendlela enye, zisetyenziselwa ukubala ubungakanani bomtya omiselweyo oqingqiweyo wobungakanani bebhloko yolwazi. Azinakubuyiselwa umva kwaye zisetyenziselwa ukukhangela ukuthembeka kwefayile.

I-MD5 ngumyalezo we-digest algorithm othatha igalelo lobude obungenakuphikiswa kwaye uvelise umyalezo we-128-bit womyalezo. Le algorithm isetyenziswa kutyikityo lwedijithali usetyenziso, ukujonga ukuthembeka, kunye nokugcinwa kwephasiwedi.

SHA

Ukukhuseleka kweAlgorithm okanye i-SHA yialgorithm evelisa umyalezo wokugcina umyalezo okhuselekileyo ngokufihlakeleyo. Zintathu izizukulwana ze-SHA algorithms: SHA-1, SHA-2, kunye SHA-3. I-SHA-1 ivelisa i-160-bit digests, ngelixa i-SHA-2 kunye ne-SHA-3 zivelisa i-256, 384, kunye ne-512-bit digests.

I-HMAC

I-Hash esekwe kwiKhowudi yokuNgqinisisa uMyalezo okanye i-HMAC luhlobo lomyalezo wokuqinisekisa ikhowudi. Isebenzisa indibaniselwano yesitshixo se-cryptographic kunye nomsebenzi we-hash njenge-SHA-1 okanye i-MD5. Isetyenziselwa ukungqinisisa kunye nokujonga ukuthembeka.




I-PKI

I-PKI imele iZiseko ezingundoqo zoLuntu kwaye ibhekisa kwizixhobo zokusebenza, isoftware, abantu, imigaqo-nkqubo kunye neenkqubo ezifunekayo ukulawula izatifikethi zedijithali. Uyilo loyilo olwenziwe ukonyusa ubumfihlo bolwazi olutshintshisanayo.

Isatifikethi esisayiniweyo sisiqinisekiso esikhutshwe nguGunyaziwe wesiQinisekiso (CA). Inesitshixo sikawonke-wonke kunye nesazisi somnini.

Isatifikethi esityikityiweyo sisatifikethi esikhutshiweyo kwaye satyikitywa nguwe. Ihlala isetyenziselwa ukuvavanya kwaye kungenjalo ayithembeki.



I-imeyile kunye nokubhala ngeDisk

Utyikityo lwedijithali

Ukutyikitywa kwedijithali kuyenziwa kusetyenziswa i-asymmetric cryptography. Iqhotyoshelwe kwidatha ehanjisiweyo kwaye imele indlela yokubonisa yokufihlakeleyo.

I-SSL

I-SSL imele iZiseko zoKhuseleko eziKhuselekileyo kwaye ibhekisa kwiprotocol yesicelo esinoxanduva lokuqinisekisa ukhuseleko lokuhambisa umyalezo kwinethiwekhi nakwi-Intanethi.

TLS

I-TLS imele uKhuseleko loLuhlu lwezoThutho kwaye ibhekisa kwiprotocol eseka unxibelelwano olukhuselekileyo lwabathengi kunye nokuqinisekisa ukuthembeka kolwazi kunye nemfihlo ngexesha lokuhambisa.

I-PGP

I-PGP imele uKhuselo oluLungileyo kwaye ibhekisa kwiprothokholi esetyenziselwa ukubethela kunye nokuseta ukuqinisekiswa kwedatha ye-cryptographic. I-PGP isetyenziselwa ukunyanzela idatha, utyikityo lwedijithali, ukubethela nge-imeyile / ukuguqulela, kunye nolunye ulwazi olubuthathaka.

Ukubhalwa kweDisk

Ukubhalwa kweediski kubhekisa kubhalo oluntsonkothileyo lwayo yonke idatha egcinwe kwidiski. Injongo kukukhusela idatha egcinwe kwidiski kunye nokuqinisekisa ukugcinwa kwayo kuyimfihlo.



Uhlalutyo lwecryptanalysis

I-Cryptanalysis ibhekisa kwinkqubo yokuchithwa kwe-cipher kunye nokubhaliweyo okubhaliweyo. Inokuchonga ubuthathaka kwii-cryptosystems kwaye yiyo loo nto ikhuphe isicatshulwa esicacileyo kule ndawo ibhaliweyo.

Iindlela ezisetyenziswa kwi-cryptanalysis zezi:

  • I-linear cryptanalysis isetyenziswa kwiibhlokhi zebhloko
  • Umahluko kwi-cryptanalysis usetyenziswa kwii-algorithms eziphambili zeesitshixo
  • I-cryptanalysis ehlanganisiweyo isetyenziswa kwiibhlokhi zebhlokhi

Indlela yokuqhekeza ikhowudi

Iindlela ezisetyenziselwa ukulinganisa amandla e-encryption algorithm ngokwaphula ukubethela kubandakanya:

  • Inkqubo yamandla eBrute izama yonke indibaniselwano yabalinganiswa ukuba baphule ukubethela
  • Inkqubo yokuhlalutya rhoqo iphicotha ubungakanani bokwenzeka kweesimboli ezithile kwaye kusekwe kwinto eyaphula ukubethela
  • Iqhinga lokukhohlisa kunye nenkohliso lifuna ukusebenzisa iindlela zobunjineli kwezentlalo ukukhupha izitshixo kunye nokuphula ukubethela
  • Inkqubo yexesha elinye iphedi ibhekisa kubhalo olungenakuqhekeka apho isicatshulwa esicacileyo sidityaniswe nesitshixo esineeseti ezingaphindaphindwayo zoonobumba, eziveliswa ngokungacwangciswanga, kwaye zinobude obufanayo nomyalezo othunyelweyo.

Ukuhlaselwa kwe-Cryptography


  • Ukuhlaselwa kweCiphertext-kuphela luhlaselo apho umhlaseli eqokelele imibhalo efihlakeleyo efuna uhlalutyo ukufumana isitshixo kunye nokubethela isicatshulwa.


  • Uhlaselo olwaziwayo luhlaselo apho umhlaseli enenxalenye yokuchasana esekwe apho afumana khona isitshixo.


  • Uhlaselo oluchongiweyo luhlaselo apho umhlaseli afumana khona isitshixo ngokuhlalutya isicatshulwa esicacileyo kunye nombhalo ohambelanayo oveliswe ngumhlaseli.


  • Uhlaselo lwe-ciphertext olukhethiweyo luhlaselo apho umhlaseli afumana isicatshulwa esicacileyo kwiseti yeefayile ezikhethiweyo kunye nokuzama ukufumana isitshixo.


  • Ukuhlaselwa ngamandla luhlaselo apho yonke indibaniselwano enokubakho izanywa ngokuchasene nomgaqo wendlela kude kube kufunyenwe iqhosha lasekunene. Olu hlaselo ludinga ixesha elininzi kunye namandla okulungisa.


  • Uhlaselo lwesichazi-magama Uhlaselo apho umhlaseli enza isichazi-magama sokubhaliweyo kunye nesicatshulwa sayo aze asebenzise eso sichazi-magama ukwaphula ukubethela.