Ana kuma san ɓarnar guntu a matsayin decryption guda ɗaya (IC decryption). Tun da guntuwar microcomputer chips guda ɗaya a cikin samfurin hukuma an ɓoye su, ba za a iya karanta shirin kai tsaye ta amfani da mai shirye-shirye ba.
Don hana shiga mara izini ko kwafin shirye-shiryen kan-chip na microcontroller, yawancin masu sarrafa microcontrollers sun rufaffen ɓoyayyen maɓalli ko rufaffen bytes don kare shirye-shiryen kan-chip. Idan an kunna bit makullin ɓoye (kulle) yayin shirye-shirye, shirin da ke cikin microcontroller ba zai iya karanta shi kai tsaye ta hanyar mai tsara shirye-shirye na gama gari ba, wanda ake kira ɓoye ɓoye microcontroller ko ɓoyayyen guntu. Maharan MCU suna amfani da kayan aiki na musamman ko kayan aikin da aka yi da kansu, suna amfani da madauki ko lahani na software a cikin ƙirar guntu ta MCU, kuma ta hanyoyi daban-daban na fasaha, suna iya fitar da mahimman bayanai daga guntu kuma su sami shirin ciki na MCU. Ana kiran wannan guntu cracking.
Hanyar ɓarna guntu
1.Harin Software
Wannan dabara yawanci tana amfani da mu'amalar sadarwa ta na'ura mai sarrafawa da kuma amfani da ka'idoji, algorithms na ɓoyewa, ko ramukan tsaro a cikin waɗannan algorithms don kai hari. Misali na yau da kullun na harin software mai nasara shine harin farkon ATMEL AT89C jerin microcontrollers. Maharin ya yi amfani da madauki a cikin ƙirar tsarin aikin shafewa na wannan jerin ƙananan na'urori masu guntu guda ɗaya. Bayan ya goge bit ɗin makullin ɓoyewa, maharin ya dakatar da aiki na gaba na goge bayanan a cikin ƙwaƙwalwar ajiyar shirin kan-chip, ta yadda microcomputer ɗin da aka rufaffen guda ɗaya ya zama microcomputer guda ɗaya wanda ba a ɓoye ba, sannan ya yi amfani da shirye-shiryen don karanta on- guntu shirin.
Dangane da wasu hanyoyin ɓoyewa, ana iya haɓaka wasu kayan aiki don haɗa kai da wasu software don yin harin software.
2. harin gano lantarki
Wannan dabara yawanci tana lura da halayen analog na duk haɗin wutar lantarki da haɗin haɗin na'ura yayin aiki na yau da kullun tare da babban ƙuduri na ɗan lokaci, kuma yana aiwatar da harin ta hanyar lura da halayensa na lantarki. Saboda microcontroller na'urar lantarki ce mai aiki, lokacin da take aiwatar da umarni daban-daban, daidaitaccen amfani da wutar lantarki shima yana canzawa daidai da haka. Ta wannan hanyar, ta hanyar nazari da gano waɗannan canje-canje ta amfani da kayan aunawa na musamman na lantarki da hanyoyin ƙididdiga na lissafi, ana iya samun takamaiman mahimman bayanai a cikin microcontroller.
3. fasahar samar da kuskure
Dabarar tana amfani da yanayin aiki mara kyau don buge na'ura mai sarrafawa sannan ta ba da ƙarin damar kai harin. Hare-haren haifar da kuskure da aka fi amfani da su sun haɗa da hawan wutar lantarki da ƙarar agogo. Za a iya amfani da hare-haren ƙananan ƙarfin lantarki da ƙarfin wutar lantarki don musaki da'irori na kariya ko tilasta masarrafar yin ayyuka na kuskure. Masu wucewar agogo na iya sake saita da'irar kariyar ba tare da lalata bayanan da aka kare ba. Wutar lantarki da agogo na iya yin tasiri ga yanke hukunci da aiwatar da umarni ɗaya a wasu na'urori masu sarrafawa.
4. fasahar bincike
Fasaha ita ce ta bijirar da wayoyi na cikin guntu kai tsaye, sannan a lura, sarrafa, da tsoma baki tare da microcontroller don cimma manufar harin.
Domin saukakawa, mutane sun raba dabarun kai hari guda hudu da ke sama zuwa kashi biyu, daya shine harin kutse (harbin jiki), irin wannan harin yana bukatar lalata kunshin, sannan a yi amfani da kayan gwajin semiconductor, microscopes da micro-positioners a cikin dakin gwaje-gwaje na musamman. Yana iya ɗaukar sa'o'i ko ma makonni don kammalawa. Duk dabarun microprobing hare-haren wuce gona da iri ne. Sauran hanyoyin guda uku sune hare-haren da ba na cin zarafi ba, kuma microcontroller da aka kai harin ba zai lalace ta jiki ba. Hare-haren da ba na kutsawa ba yana da haɗari musamman a wasu lokuta saboda kayan aikin da ake buƙata don hare-haren ba za a iya yin su ba sau da yawa ana iya gina su da haɓakawa, don haka suna da arha.
Yawancin hare-haren da ba sa kai-kawo a kai suna buƙatar maharin ya kasance yana da ingantaccen ilimin sarrafawa da ilimin software. Sabanin haka, hare-haren bincike masu cin zarafi baya buƙatar ilimin farko da yawa, kuma ana iya amfani da ɗimbin fasahohi iri ɗaya a kan samfura da dama. Sabili da haka, hare-hare akan microcontrollers sau da yawa suna farawa daga injiniyan juzu'i, kuma ƙwarewar da aka tara tana taimakawa wajen haɓaka dabarun kai hari mai rahusa da sauri.