Save Digital Signature (ECID)
All owners of iPhone 3G, 3GS, 4 and iPad, who in the future want to have a jailbroken phone despite the firmware version, must save the ECID certificate.
Attention! The digital signature is saved only for the current version of the firmware. This means that after the release of iOS 4.1, you will not be able to save the signature from 4.0.1, even though you have it installed.
So click on the button as early as possible!
The easiest way is to save the SHSH files on Saurik's servers in Cydia. So, launch Cydia and click on Make my life easier, thanks!
After that, your device will wait for the request to be processed and you will see the following inscription on top - This device has a pending TSS request , but as soon as the signature is saved, the message will change to This device has SHSHs on file for iPhone OS: 4.0 , where the numerical value corresponds to the version firmware on which you are guaranteed to be able to roll back.
Everything, the signature is saved, now in the future this phone can be easily jailbroken!
You can also save the signature on your computer, this is the most reliable option, but I advise you to start with Cydia.
To do this, download the program TinyUmbrella 4.01.03
TinyUmbrella 4.01.03 [ ] [ ] [ ]
After starting the program, connect the device to the computer and click on the "Save my SHSH" button and after a while your signature will be saved on the PC in the folder C: \ Users \ Username \ .shsh \