UPDATE: This howto is obsolete, please follow the steps mentioned on Save SHSH Blobs of your iPad/iPhone and iPod touch before upgrading to iOS 4.2
SHSH Blob needs to be saved if you want to jailbreak your iPad. If you don’t save SHSH Blob all your Jailbroken functionality will be lost if Apple may release the new firmware. Why it needs to be saved? we will see later in more detail. But first let me tell you what the heck is SHSH Blobk or ECID SHSH anyway?
SHSH Blobs are basically signature of your firmware installed on your iDevice. They are checked against Apple servers and allow you to restore a particular firmware on your device. This applies to all devices including iPhone, iPod touch and iPad. When Apple releases new firmware it stops signing the old firmware and hence you can’t restore back to older firmware through iTunes.
You must have got the idea why you need to save SHSH Blob before, let me give you a bit more insight on this. The developer of Cydia has configured a server which provides Apple like verification service and can save your SHSH signature to allow you to downgrade or restore the older firmware. So if you don’t have your SHSH blob saved and update your firmware you know that you will lose your jailbroken functionality, not only that but you won’t be able to downgrade to older firmware or rejailbreak your device.
There are numerous ways to store SHSH blob but the most easiest is to use AutoSHSH. Follow the steps below to save your SHSH using AutoSHSH.
Step 1: Backup your device. Open iTunes connect your iPad and make a backup.
Step 3: Connect your device in recovery mode by turning your iPad off and then pressing “Home” button while connecting to USB cable, keep Home button pressed until you see “Connect to iTunes” message on your iPad.
Step 4: Start AutoSHSH which you downloaded in Step 1.
Step 5: Click the “Grab my SHSH blobs Automatically” button.
Step 6: AutoSHSH will ask you the location to store your blobs. Select a safe location.
Congratulations you have saved your SHSH blobs, now you can go and jailbreak your iPad.