ECID allows to bypass the server security implemented by Apple to fight against the Jailbreak.
By saving your ECID you guarantee the possibility of downgrading to 4.0!
Example. In the future ^^ Spirit for iOS 4 comes out, you jailbreak your iPhone 4 under iOS 4.0.1 or 4.0 whatever. But there Apple releases 4.1 and inadvertently install the update, thus canceling the Jailbreak. You will then want to go back to 4.0 to again Jailbreak your iPhone 4.
But when you indicate 4.0 to iTunes you get a nice error message like “1015 – blablabla”
Basically, you cannot install 4.0 because our server indicates that the latest firmware available is 4.1!
This is where ECID comes in. Thanks to it you will be able to tell iTunes:
“The latest firmware available is 4.0”
And there magic, restoration in 4.0 then becomes possible 😉
This is one of the possibilities offered by ECID, there are others?.
This tutorial works for the following devicess
- iPhone 3GS
- iPod Touch 3G
- iPhone 4
- iPad (wifi and 3G)
Important. No need to be running iOS 4.0.1 to save ECID 4.0.1, if you are in 4.0 it’s fine 😉
First, launch the software. If you are under Windows it is possible that your fire block the software. A window like this one then appears:
Click on “Allow access”
Connect your device to the computer. Close iTunes.
Click on “Start TSS Server”
Click on “Save My SHSH”.
Thanks to the TSS server launched previously, your SHSH was automatically sent to the Saurik servers. So when you open Cydia, it tells you at the top of the home page that your ECID is saved;)
The iPhone3GSystem team
Thanks to Chotchot for the signage