1. gtakers's Avatar
    As I understand it, many people are stuck being unable to downgrade from 3.1.3 to 3.1.2, unless they backed up their SHSH file. . .I am curious about why a user must have backed up his own SHSH to downgrade. . . why can't someone else's SHSH be borrowed, or generated somehow?

    Thanks for any info about SHSH files and helping me understand how Apple tries to keep us behind bars!
    2010-03-24 02:07 AM
  2. Cer0's Avatar
    Only the 3GS has to worry about SHSH. Basically it is like a key to check and download current firmware from Apple. It is needed to be signed to restore. But Apple stops signing older firmware so Saurik has a server that fakes the signatre checks and lets users restore to an older firmware as long as they had his server sign it before. If I don't have 3.1.2 signed and stored on his server then I can't go back to that one. But if I had 3.1 signed I can go back to that step; but still limited to what he has saved and the current one.
    2010-03-24 02:10 AM
  3. gtakers's Avatar
    If I had a friend who backed up his 3.1.2 SHSH with Saurik, could I use that one to downgrade my iphone?

    I know the SHSH involves the ECID, which is different for every phone, but could there be a way to modify your previously Saurik-Signed SHSH to identify itself as if it were an SHSH from my phone?

    I guess if I try to put it simply, my question is. . . Why does it have to be my SHSH?
    2010-03-24 02:29 AM
  4. Cer0's Avatar
    What his server does is grabs the keys when that firmware is current. So the SHSH will have different footprint for each firmware version that he can only grab at the time the firmware is current. Example: I am going to skip 3.1.3 so there will be no way I can go back to that once a different firmware becomes current. Because I never had his server get my "keys" for that firmware.

    Also there are many topics on here about changing your ECID on the board. I saw a post a little bit ago about it and a person refered to the other posts that has been talked about.
    2010-03-24 03:03 AM
  5. gtakers's Avatar
    Do you know anyone who may be able to explain why YOUR shsh will not work to restore MY iphone?
    2010-03-24 05:20 AM
  6. Cer0's Avatar
    Because of the keys, each phone is unique and has its own unique key. Which is probably hardcoded in. Just like each phone has it's own IMEI number.
    2010-03-24 05:44 AM
  7. dhamien's Avatar
    Do you know anyone who may be able to explain why YOUR shsh will not work to restore MY iphone?
    It was just explained to you.
    2010-03-24 09:49 PM