Ofufuza ochokera ku French National Institute for Research in Informatics and Automation (INRIA) ndi Nanyang Technological University (Singapore) bwino ku algorithm ya SHA-1, yomwe imathandizira kwambiri kupanga zolemba ziwiri zosiyana ndi ma SHA-1 hashes omwewo. Chofunikira cha njirayo ndikuchepetsa magwiridwe antchito a kugunda kwathunthu ku SHA-1 mpaka , momwe kugunda kumachitika pamene ma prefixes ena alipo, mosasamala kanthu za deta yonse mu seti. Mwanjira ina, mutha kuwerengera ma prefixes awiri omwe adafotokozedweratu ndipo ngati mungaphatikizepo chikalata chimodzi ndi china kwachiwiri, zotsatira za SHA-1 za mafayilowa zidzakhala zofanana.
Kuwukira kwamtunduwu kumafunikirabe kuwerengera kwakukulu ndipo kusankha ma prefixes kumakhalabe kovuta kwambiri kuposa kusankhira komwe kumachitika nthawi zonse, koma kuchita bwino kwa zotsatira zake ndikokwera kwambiri. Pomwe mpaka pano njira yachangu kwambiri yopezera ma prefixes akugunda mu SHA-1 imafunikira ma 277.1 opareshoni, njira yatsopanoyi imachepetsa kuchuluka kwa mawerengedwe kuchokera pa 266.9 mpaka 269.4. Ndi mlingo uwu wa makompyuta, mtengo woyerekeza wowononga ndi wocheperapo madola zikwi zana limodzi, zomwe zili mkati mwa njira zamabungwe anzeru ndi makampani akuluakulu. Poyerekeza, kufunafuna kugunda kokhazikika kumafuna pafupifupi ma 264.7 ma opareshoni.
Π Kutha kwa Google kupanga mafayilo osiyanasiyana a PDF okhala ndi SHA-1 hashi yomweyo chinyengo chophatikizira kuphatikiza zikalata ziwiri kukhala fayilo imodzi, kusintha gawo lowoneka ndikusintha chizindikiro chakusanjikiza kumalo komwe kugunda kumachitika. Ndi ndalama zofananira zothandizira (Google idakhala chaka chowerengera pagulu la ma 1 GPU kuti mupeze kugunda koyamba kwa SHA-110), njira yatsopanoyo imakulolani kuti mukwaniritse machesi a SHA-1 pamaseti awiri osagwirizana. Kumbali yothandiza, mutha kukonzekera ziphaso za TLS zomwe zimatchula madera osiyanasiyana, koma kukhala ndi ma SHA-1 hashes omwewo. Izi zimalola olamulira osakhulupirika kuti apange satifiketi ya siginecha ya digito, yomwe ingagwiritsidwe ntchito kuvomereza ziphaso zabodza pamadomeni osagwirizana. Nkhaniyi itha kugwiritsidwanso ntchito kusokoneza ma protocol omwe amadalira kupewa kugundana, monga TLS, SSH, ndi IPsec.
Njira yomwe akufuna kufufuza ma prefixes a kugunda ikuphatikizapo kugawa mawerengedwewo m'magawo awiri. Gawo loyamba limayang'ana midadada yomwe ili pafupi ndi kugundana mwa kuyika masinthidwe osinthika mumtundu womwe wafotokozedwa kale. Pa gawo lachiwiri, pamlingo wa midadada, kusiyana komwe kumachitika chifukwa cha kusiyana kumafananizidwa ndi zigawo ziwiri zomwe zimatsogolera kugundana, pogwiritsa ntchito njira zachisankho zachikhalidwe.
Ngakhale kuti kuthekera kwachidziwitso cha kuukira kwa SHA-1 kunatsimikiziridwa kale mu 2005, ndipo pochita kugundana koyamba kunali. mu 2017, SHA-1 ikugwiritsidwabe ntchito ndipo ikugwiritsidwa ntchito ndi miyezo ndi matekinoloje ena (TLS 1.2, Git, etc.). Cholinga chachikulu cha ntchito yomwe idachitika chinali kupereka mkangano wina wokakamiza kuti asiye kugwiritsa ntchito SHA-1 nthawi yomweyo, makamaka pamasitifiketi ndi ma signature a digito.
Kuphatikiza apo, zitha kuzindikirika cryptanalysis ya block ciphers , yopangidwa ndi US NSA ndikuvomerezedwa ngati muyezo mu 2018 .
Ofufuzawo adatha kupanga njira yopezeranso kiyi yachinsinsi kutengera mawiri awiri odziwika bwino ndi mawu olembedwa. Ndi zida zochepa zamakompyuta, kusankha kiyi kumatenga maola angapo mpaka masiku angapo. Chiwopsezo cha chiwopsezochi chikuyerekezeredwa ndi 0.25, ndipo chothandiza cha zomwe zilipo ndi 0.025.
Source: opennet.ru