A umsebenzi hashi ngu: yintoni, kutheni yaye kwenzeka ntoni

Ngokuqhelekileyo, xa ulanda yimisinga okanye iifayile ngqo ngokwabo kwi inkcazo kukho into efana «ad33e486d0578a892b8vbd8b19e28754» (umzekelo, kwi ex.ua), ngokufuthi kunye nenqaku «MD5». Le hashi ikhowudi - result ovelisa umsebenzi asa emva kokuba kuqhutywe data engenayo. In IsiNgesi le asa ibonisa isiphithiphithi, intsangu, ukhula, okanye isidlo inyama okuthambile kunye nemifuno. Ukuwufunda lo asa kunzima kakhulu, singatsho ukuba cishe engenakwenzeka. Ngoko ke nanku umbuzo: "Kufuneka Kutheni simele sonke ezi imisebenzi asa, ukuba ukumnika gibberish ongaqondakaliyo, nto leyo nayo ayikwazi ziqala?". Oku kuya kuxutyushwa kweli nqaku.

Yintoni umsebenzi asa, yaye isebenza njani?

Lo msebenzi yenzelwe ukuguqula idatha engenayo imali lokungavinjwa enkulu ngenxa yobude ezisisigxina. Inkqubo kakhulu inguqu enjalo kuthiwa hashing, yaye isiphumo - a asa okanye ikhowudi hashe. Maxa wambi nkqu esebenzisa igama elithi "fingerprint" okanye "umyalezo Digest", kodwa practice ukuba anqabe kakhulu. Kukho ubuchule ezininzi ezahlukeneyo ukuguqula indlela nayiphi dataset ngolandelelwano ezithile iisimboli ubude ethile. I algorithm lusetyenziswa kakhulu ngokuba MD5, nolwathi lwaphuhliswa kwangethuba kangangoko 1991. Nangona ukuza kuthi ga ngoku, MD5 kukuba isuntswana lixesha kwaye ukusetyenziswa akunconywa, kusesemini ngeenxa cwaka, yaye ngokufuthi endaweni "ikhowudi asa" kwi sites bhala nje MD5, kwaye ubonise ikhowudi ngokwayo.

Kutheni sifuna umsebenzi hashi?

Ukwazi yoko, cishe akunakwenzeka ukuba ukujonga idatha yoqobo, kodwa iinkcukacha ezifanayo engenayo ukunika isiphumo esifanayo. Ngoko ke, lo msebenzi asa (ekwabizwa ngokuba umsebenzi ngokwenqanawaComment) lidla ngokusetyenziswa ukugcina ulwazi olubuthathaka kakhulu ezifana password yakho, igama lomsebenzisi, inombolo ye-ID kunye nezinye iinkcukacha zobuqu. Kunokuba ngokuthelekisa ulwazi wangena ngumsebenzisi, nabo igcinwe kwiziko ledatha, kukho uthelekiso hashes. Oku kuqinisekisa ukuba kukho ukuvuza ngengozi lolwazi, akukho namnye unako ukuthatha ithuba data kubalulekile ukuba iinjongo zabo. Ngokuthelekisa ikhowudi asa kwakhona lula ukujonga ukuchaneka wokulanda iifayile kwi Internet, ingakumbi xa unxibelelwano ukuphazamiseka yenzekile ngexesha download.

Hashe: oko ke t

Kuxhomekeka umsebenzi wakho asa yendawo inga yenye iintlobo ezintathu:

1. Umsebenzi ukukhangela ukuthembeka kolwazi

Xa transmission data womnatha, kukho ekubaleni asa ipakethe, yaye ezi ziphumo wadlulisela kunye ifayile. Xa walunyukiswa kwakhona ayinakubalwa ikhowudi asa kwaye kuthelekiswa nexabiso afunyenwe network. Ukuba ikhowudi ayihambiselani, libonisa imposiso, kwaye impahla yezimoshakeleyo kuya kukhutshelwa kwakhona. Xa yokubala umsebenzi kwisantya enjalo fast, kodwa inani elincinane amaxabiso asa kunye nozinzo amahlwempu. Umzekelo hlobo: CRC32, nto leyo eye amaxabiso 232 kuphela ezahlukeneyo.

2. Umsebenzi lokufihla

Olu hlobo iyasetyenziswa ukukhusela nxamnye kusebenziso olungavumelekanga (ND). Amvumela ukuba ukhangele ukuze ubone enoba kukho urhwaphilizo idatha ngenxa LP ngexesha ukutshintshwa iifayile ngapha komsebenzi womnatha. asa bokwenene ifumaneka esidlangalaleni, kulo mzekelo, njengoko asa ifayile efunyenweyo ayikwazi ukubalwa ngokusebenzisa ezininzi iinkqubo ezahlukeneyo. iimpawu ezinjalo ubomi obude kunye nokusebenza ezinzileyo, kanye Ukufuna yangqubana (neentelekiso ezinokwenzeka iziphumo ezivela data umthombo ezahlukeneyo) inzima kakhulu. imisebenzi enjalo zisetyenziselwa ukugcina kwiziko ledatha igama (SH1, SH2, MD5) kunye nezinye iinkcukacha ezixabisekileyo.

3. Umsebenzi iyilelwe ukwenza isakhiwo data esebenzayo

Injongo yalo kunokuba umbutho indawo enocwangco ulwazi enalo kwisakhiwo ekhethekileyo, ekuthiwa kwetafile hashe. Le theyibhile ikuvumela ukuba ukongeza ulwazi olutsha, cima ulwazi, kwaye phendla i data efunekayo ngesantya esiphezulu kakhulu.