A umsebenzi hashi kuyinto: kuyini, kungani futhi kwenzekani

Ngokuvamile, uma ulanda zezifufula noma amafayela ngqo ngokwabo encazelweni kukhona into efana «ad33e486d0578a892b8vbd8b19e28754» (isibonelo, ex.ua), ngokuvamile inothi «MD5». Le khodi hashi - umphumela ukuthi okukhiphayo umsebenzi hashi ngemva kokucubungula idatha engenayo. NgesiNgisi le hashi kubonisa ukudideka, insangu, ukhula, noma isidlo inyama nengulube nemifino. Ukuqhaqha hashi kunzima kakhulu, singasho ukuthi cishe engenakwenzeka. Khona-ke kuphakama umbuzo: "Kungani sidinga zonke lezi imisebenzi hashi, uma benikela gibberish engaqondakali, nakho ayikwazi ziqala?". Lokhu kuzoxoxwa ngakho kulesi sihloko.

Uyini umsebenzi hashi, futhi kusebenza kanjani?

Lokhu umsebenzi yakhelwe ukuguqula idatha engenayo lemali ezinqumela ezinkulu ngenxa obuphelele isilungisiwe. kakhulu inqubo izinguquko libizwa hashing, futhi umphumela - a hashi noma ikhodi hashi. Ngezinye izikhathi ngisho usebenzisa igama elithi "zeminwe" noma "umyalezo Ukugaya", kodwa umkhuba zingabantu lingandile kangako. Kukhona ama-algorithm eziningi zendlela okuguqula iyiphi kudathasethi ilandelane ezithile izimpawu ubude ezithile ezahlukene. Indlela esetshenziswa kabanzi i-algorithm ngokuthi MD5, olwakhiwa kudala njengoba 1991. Naphezu kweqiniso lokuthi kuze kube manje, MD5 kancane yisikhathi futhi ukusetshenziswa is hhayi Kunconywa, kusenzima namanje emhlabeni, futhi ngokuvamile esikhundleni "ikhodi hashi" kumasayithi nje ukubhala MD5, futhi abonisa ikhodi ngokwayo.

Kungani sidinga umsebenzi hashi?

Ukwazi yalokho, cishe akunakwenzeka ukuthola ukuthi idatha yoqobo, kodwa idatha efanayo engenayo ukunikeza umphumela ofanayo. Ngakho-ke, umsebenzi hashi (ebuye ibizwe ngokuthi umsebenzi convolution) ngokuvamile asetshenziselwa ukugcina ulwazi olubucayi kakhulu efana nephasiwedi yakho, igama lomsebenzisi, inombolo kamazisi kanye olunye ulwazi lomuntu siqu. Esikhundleni Ngokuqhathanisa ulwazi angena ngumsebenzisi, nalabo elondolozwe ku database, kukhona Ukuqhathanisa hashes. Lokhu kuqinisekisa ukuthi uma ukuvuza ngephutha kolwazi, akekho ingakwazi idatha ebalulekile izinjongo zabo. Ngokuqhathanisa ikhodi hashi futhi elula ukuhlola ngokunemba ukulanda amafayela kusuka ku-intanethi, ikakhulukazi uma ukuxhumana ukuphazamiseka kwenzeka ngesikhathi thwebula.

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Kuye uya khona hashi umsebenzi kungaba omunye ezintathu izinhlobo:

1. Umsebenzi ukuhlola ubuqotho ulwazi

Lapho ukudluliswa kwedatha inethiwekhi, kukhona ekubalweni iphakethe hashi, futhi lokhu yi nayo ngocansi kanye ifayela. Lapho ethola futhi ngekhompyutha ikhodi hashi futhi uma kuqhathaniswa nenani etholwe inethiwekhi. Uma Ikhodi ayifani, kubonisa nephutha, futhi iphakethe ezilimele kuzophinda adlulisiwe. Ngo izibalo umsebenzi ngesivinini okusheshayo kodwa inombolo encane hashi amagugu nokuzinza abampofu. Isibonelo salolu hlobo: CRC32, okuyinto has amagugu ezihlukahlukayo 232 kuphela.

2. Umsebenzi wokubhala ngezimpawu

Lolu hlobo isetshenziselwa ukuvikela nokufinyelela okungagunyaziwe (ND). Bavumela ukuba uhlole ukuze ubone ukuthi kukhona idatha inkohlakalo ngenxa ye LP ngesikhathi kuthuthwa izakhiwo amafayela ngenethiwekhi. hashi True lutholakala esidlangalaleni, kulesi simo, njengoba wathola ifayela hashi kungenziwa ngekhompyutha usebenzisa sebuningini izinhlelo ezahlukene. izici ezinjalo impilo ende futhi operation esitebeleni, futhi ucinge ukushayisana (okufanayo kungenzeka imiphumela kusuka kwidatha emthonjeni ohlukile) luyindida kakhulu. Imisebenzi enjalo asetshenziselwa isitoreji database iphasiwedi (SH1, SH2, MD5) kanye neminye imininingwane eyigugu.

3. Umsebenzi yakhelwe ukudala i isakhiwo idatha kahle

Inhloso yayo esikhundleni inhlangano icwecwe futhi ngokuhleleka ulwazi isakhiwo ekhethekile, okuthiwa etafuleni hashi. Leli thebula ikuvumela ukuba wengeze ulwazi olusha, susa ulwazi, futhi useshe idatha edingekayo ngesivinini esikhulu.