He mahi hae ko: he aha te mea te reira, he aha me aha tupu

E mea pinepine, ka tikiake awa kōnae ranei tika ratou i roto i te whakaahuatanga i reira he tahi mea rite «ad33e486d0578a892b8vbd8b19e28754» (hei tauira, i roto i te ex.ua), maha ki te tuhipoka «md5». Tenei waehere hae - te hua e whakaputanga he mahi hae i muri i te tukatuka i te raraunga taumai. I roto i te reo Ingarihi i te hae tohu whakama, tarukino, tarutaru, ranei te rihi o te kai mōrohe me huawhenua. Wetemuna Ko te tino uaua te hae, ka taea e tatou te mea e ko te reira i whakaritea e taea. Na ka whakatika te pātai: "He aha te mahi i hiahia katoa o enei tatou mahi hae, ki te hoatu e ratou he parau maamaa te hano, e kore e taea te deciphered hoki?". Ka tenei e lāulea i roto i tenei tuhinga.

He aha te mea he mahi hae, me pehea e mahi i te reira?

hangaia ana tēnei mahi te ki te tahuri te raraunga taumai nui takirihia nui rite ki te hua o te roa whakaritea. huaina te tukanga rawa o te huringa taua te hashing, me te hua - he hae waehere hae ranei. I te tahi taime noa te whakamahi i te kupu "tapumati" ranei "whakahanumi karere", engari i roto i te mahi he nui e ono ratou. He maha hātepe rerekē o te āhua o ki te taui i tetahi huingararaunga i roto i te tetahi raupapa o tohu o etahi roa. Ko te hātepe tino whānui whakamahia i huaina md5, i whakawhanakehia rite wawe rite 1991. Ahakoa te meka e ki te rā, ko te wahi tawhito md5 me kore te te whakamahi tūtohu, he reira tonu ko tonu a tawhio noa, a maha hei utu o "waehere hae" i runga i ngā pae tuhituhi noa md5, a ka tohu ki te waehere iho.

He aha e hiahia ana tatou he mahi Hash?

E matau ana te hua, he mea i whakaritea e taea ki te whakatau i te raraunga taketake, engari te raraunga taumai taua hoatu te hua taua. Na reira, ko te mahi hae (i huaina ano hoki he mahi convolution) Kei te maha whakamahia ki te rokiroki i ngā mōhiohio rawa tairongo pēnei i tō kupuhipa, ingoa kaiwhakamahi, tau ID me ētahi atu mōhiohio whaiaro. Engari o te whakatairite i te mōhiohio tomo i te kaiwhakamahi, me te hunga rongoa i roto i te pātengi raraunga, i reira te mea he rite o Hashes. Ka āta whakarite tēnei e i roto i te take o te leakage kōpeka o ngā mōhiohio, ka taea e kore tetahi tango i te rawa o raraunga nui mo ratou ake take. Na roto i te te whakatairite i te waehere hae he hoki watea ki te tirohia i te tika o te tikiake kōnae i te Internet, rawa, ki te puta tauwhatinga kōrero i roto i download.

Hash: he aha e t ratou

Runga anō i tō hae mahi ūnga e taea e tetahi o e toru ngā momo:

1. ki te mahi tirohia te tapatahi o te mōhiohio

A, no te he tuku raraunga whatunga, i reira ko te tātaitanga o te pākete hae, a ka te hoki tuku tahi tenei hua ki te kōnae. To ratou fariiraa computed ano waehere hae me whakaritea ki te uara whiwhi e te whatunga. Ki te kore e ōrite te waehere, tohu reira he hapa, a ka te mōkihi pakaru kia whakawhitia ano. I roto i te taua i te tātai mahi tere nohopuku engari he maha iti o ngā uara hae me te pūmautanga rawakore. He tauira o tenei momo: CRC32, e kua 232 anake ngā uara rerekē.

2. Ko te mahi cryptographic

Tēnei momo whakamahia te ki te tiaki ki te whakaurunga (Nd). tukua ratou ki a koe tirohia ki te kite ranei i reira ko te pirau raraunga rite ki te hua o te LP i roto i te whakawhitinga o ngā kōnae i runga i te whatunga. Ko hae pono e wātea ana nuitia, i roto i tenei take, kia rite ki taea te computed te hae kōnae riro mā te whakamahi i te plurality o ngā hōtaka rerekē. Taua āhuatanga roa te ora, me te mahi pūmau, me te rapu mō collisions (kēmu taea hua i rerekē raraunga pūtake) Ko te tino uaua. E whakamahia taua mahi mō te rokiroki i roto i te pātengi raraunga kupuhipa (SH1, SH2, MD5) me ētahi atu mōhiohio tino.

3. hangaia te mahi te ki te hanga i tētahi hanganga raraunga tōtika

Ko tōna whakaaro, ko te pai whakahaere kiato, me te maau o ngā mōhiohio i roto i te hanganga motuhake, e kiia nei ko te tepu hae. Tenei tepu taea ki a koe te tāpiri i ngā mōhiohio hou, muku mōhiohio, ka rapu i te raraunga e hiahiatia ana i kīia e tiketike rawa.