With the release of iOS 4.2 scheduled for Friday, November 12th, the wisest thing you can do today is to save your iPhone iOS 4.1 SHSH blobs either on Cydia, or to your local hard drive with TinyUmbrella. Saving your SHSH blobs will be extremely helpful if you ever want to downgrade your iPhone to previous firmware version. You will be so glad that you did it. Don’t worry, it’s dead simple.
If you have a jailbroken iPhone, Cydia can do this for you automatically. However, to give you 100% assurance, you can always use TinyUmbrella.
Follow the steps below:
Step 1: Download TinyUmbrella from here. (Note: this website is blocked in China)
Step 2: Launch TinyUmbrella and plug in your iPhone. TinyUmbrella will automatically detect your iPhone and your current iOS version.
Step 3: Click “Save My SHSH”.
Step 4: That’s it! Just like the image above, you should get a message saying your SHSH blobs were successfully saved both locally and on Saurik’s servers.
If you ever accidentally upgrade to a newer iOS, you can always downgrade to iOS 4.1.
Warning: Upgrading to iOS 4.2 will also upgrade your baseband/modem firmware to 5.15.04 and currently there is no way to revert to your old baseband and there is no software unlock available! However, you might want to consider our hardware downgrade service here.