How To: Save Your SHSHs (Required For Downgrading)
In order to downgrade an iPhone 3GS, iPhone 4, iPad (Wifi and 3G), iPod Touch 2G MC or iPod Touch 3G you need to save what is called an SHSH blob. If you have any other iDevice than it isnt required to downgrade.
You DO NOT need to be jailbroken to do this!
What is an SHSH blob and why is it required?
Previously when jailbreaking the Dev Team would find an exploit in the iDevice's iOS (such as iBoot) and the Dev Team could get past updates by reusing these already Apple approved exploitable files to jailbreak. Essentially they would use a 2.1 iBoot that was exploitable and reuse it in place of a 2.1+ iBoot.
Apple has since stopped this by using SHSH files when updating/downgrading iOS firmware. Whenever updating or downgrading, iTunes checks with Apples severs if the currently iOS being used is the latest, if it is an SHSH blob is given to iTunes to continue, if not, then it stops.
The Steps
Navigate to this page and download TinyUmbrella in the right hand side for your appropriate computer. Once its done downloading open it up (click through any popups and allow it to run) and you will be presented with this:
![]()
Connect your iDevice (iPhone 4, etc) and wait for it to be recognized.
![]()
Click "Save My SHSH".
![]()
Your done! Your SHSH is stored on your computer and also on Cydia's severs. In the event that you accidentally update, you can downgrade the iOS that you saved the SHSH for and jailbreak.
Note: A SHSH will only work for the iOS firmware that is was created on. An SHSH for iOS 3.x will not work for iOS 4.x
In order to downgrade an iPhone 3GS, iPhone 4, iPad (Wifi and 3G), iPod Touch 2G MC or iPod Touch 3G you need to save what is called an SHSH blob. If you have any other iDevice than it isnt required to downgrade.
You DO NOT need to be jailbroken to do this!
What is an SHSH blob and why is it required?
Previously when jailbreaking the Dev Team would find an exploit in the iDevice's iOS (such as iBoot) and the Dev Team could get past updates by reusing these already Apple approved exploitable files to jailbreak. Essentially they would use a 2.1 iBoot that was exploitable and reuse it in place of a 2.1+ iBoot.
Apple has since stopped this by using SHSH files when updating/downgrading iOS firmware. Whenever updating or downgrading, iTunes checks with Apples severs if the currently iOS being used is the latest, if it is an SHSH blob is given to iTunes to continue, if not, then it stops.
The Steps
Navigate to this page and download TinyUmbrella in the right hand side for your appropriate computer. Once its done downloading open it up (click through any popups and allow it to run) and you will be presented with this:
Connect your iDevice (iPhone 4, etc) and wait for it to be recognized.
Click "Save My SHSH".
Your done! Your SHSH is stored on your computer and also on Cydia's severs. In the event that you accidentally update, you can downgrade the iOS that you saved the SHSH for and jailbreak.
Note: A SHSH will only work for the iOS firmware that is was created on. An SHSH for iOS 3.x will not work for iOS 4.x
