Biskey Generation (Downgrade Firmware)

Discussion in 'Switch - Exploits, Custom Firmwares & Soft Mods' started by momocop, Jul 16, 2019.

  1. momocop
    OP

    momocop Advanced Member

    Newcomer
    2
    Nov 14, 2010
    United States
    I'm currently in the process of downgrading my Switch from 8.1.0 to 6.0.0.

    Following the steps to downgrade using PC: https://switch.homebrew.guide/usingcfw/manualchoiupgrade


    I'm at the step for BisKey deriving by using this website: https://www.sdsetup.com/biskeygen

    When i load my fuses or Tsec files nothing happens after running the pressing Derive.

    I see that shchmue says the fuse file format was changed.

    I ran a lockpick_rcm and got bis_keys.

    Is bis_key_00 the crypto and bis_key_source the tweak key?


    ----

    Got answers to my questions! Thank so much everyone. Please close this thread!
     
    Last edited by momocop, Jul 16, 2019
  2. Masamune3210

    Masamune3210 GBAtemp Regular

    Member
    3
    Apr 23, 2016
    United States
    If I'm not mistaken the first half of the key is the crypto, and the second half is the tweak. At least, that is how hacmount handles it
     
  3. hexagonlux

    hexagonlux Member

    Newcomer
    1
    Jun 15, 2019
    United States
    is it possible to generate bis keys from tsec and sbk? I have a raw nand dump as well as fuse and key backups from a broken switch and would love to retrieve save data from it.
     
  4. Masamune3210

    Masamune3210 GBAtemp Regular

    Member
    3
    Apr 23, 2016
    United States
    Not sure sorry
     
  5. Ericjwg

    Ericjwg GBAtemp Psycho!

    Member
    8
    Jul 2, 2015
    Canada
    lockpick dump doesnt separate crypto and tweak. u need to manually split them.
    first 32 digits is crypto, and rest is tweak
     
  6. Undwiz

    Undwiz GBAtemp Regular

    Member
    3
    Mar 25, 2019
    United States
    Why downgrade ? Really dang pointless
     
    satel likes this.
Loading...