CRC-32C Hash Code Kalkuleta

Cyclic Redundancy Check (CRC) lambar gano kuskure ce da aka saba amfani da ita don gano sauye-sauye na bazata zuwa danyen bayanai. Duk da yake ba aikin zanta ba a zahiri, CRC-32 ana kiransa da zanta saboda ikonsa na samar da ƙayyadadden fitarwa (32 ragowa) daga shigarwar mai tsayi mai tsayi. Sigar da aka gabatar akan wannan shafin shine bambance-bambancen CRC-32C, wanda shine sabon sigar, “mafi wayo” (mafi kyawun gano kuskure) sigar wanda galibi ana haɓaka kayan masarufi akan CPUs na zamani (ta hanyar SSE 4.2).

Cikakken bayyanawa: Ban rubuta takamaiman aiwatar da aikin hash da aka yi amfani da shi akan wannan shafin ba. Daidaitaccen aiki ne wanda aka haɗa tare da yaren shirye-shiryen PHP. Na yi mahaɗin yanar gizo ne kawai don sanya shi a fili a nan don dacewa.

Game da CRC-32C Hash Algorithm

Ni ba masanin lissafi ba ne, amma zan yi ƙoƙarin bayyana wannan aikin hash tare da kwatanci mai sauƙi. Ba kamar yawancin ayyukan hash na sirri ba, ba algorithm ba ne mai rikitarwa, don haka zai yi kyau ;-)

Ka yi tunanin kana aika wasiƙa a cikin wasiƙar, amma kana damuwa cewa za ta iya lalacewa kafin ta isa wurin mai karɓa. Dangane da abin da ke cikin wasiƙar, kuna ƙididdige adadin CRC-32 kuma ku rubuta hakan akan ambulaf. Lokacin da mai karɓa ya karɓi wasiƙar, shi ko ita kuma za su iya lissafta cak ɗin su ga ko ya yi daidai da abin da kuka rubuta. Idan ya faru, ba a lalata wasiƙar ba ko canjawa a hanya.

Yadda CRC-32 ke yin wannan tsari ne mataki huɗu:

Mataki 1: Ƙara Wasu Ƙarin Sarari (Padding)

• CRC tana ƙara ɗan ƙarin ɗaki a ƙarshen saƙon (kamar tattara gyada a cikin akwati).
• Wannan yana taimaka masa gano kurakurai cikin sauƙi.

Mataki na 2: Mai Mulkin Sihiri (The Polynomial)

• CRC-32 yana amfani da "mai mulki" na musamman don auna bayanai.
  • Ka yi la'akari da wannan mai mulki kamar tsarin kututturewa da tsagi (wannan shi ne yawan adadin, amma kada ka damu da wannan kalma).
  • Mafi na kowa "mai mulki" na CRC-32 shine tsayayyen tsari.

Mataki na 3: Zazzage Mai Mulki (Tsarin Rarraba)

• Yanzu CRC tana zazzage mai mulki a kan saƙon.
  • A kowane wuri, yana bincika idan kumbura da tsagi sun yi layi.
  • Idan ba su yi layi ba, CRC tana yin rubutu (ana yin wannan ta amfani da XOR mai sauƙi, kamar kunnawa ko kashewa).
  • Yana ci gaba da zamewa da jujjuya maɓalli har sai ya kai ƙarshe.

Mataki 4: Sakamakon Karshe (The Checksum)

• Bayan zazzage mai mulki a kan dukkan saƙon, an bar ku da ƙaramin lamba (tsawo 32) wanda ke wakiltar ainihin bayanan.
  • Wannan lambar kamar hoton yatsa ne na musamman don saƙon.
  • Wannan shine CRC-32 checksum.

Sigar da aka gabatar akan shafin ita ce bambance-bambancen CRC-32C, wanda ya kamata ya zama bambance-bambancen da aka fi so, musamman idan kuna amfani da CPU mai haɓaka kayan masarufi (SSE 4.2 da kuma daga baya) kuma ba kwa buƙatar dacewa da sauran bambance-bambancen.

Ina da kalkuleta don sauran bambance-bambancen kuma:

• CRC-32 Hash Code Kalkuleta
• CRC-32B Hash Code Na'ura