If you’re a jailbreaker (or want to be), then you may have gotten wind of SHSH blobs. Andrew posted a tutorial on how to save them using TinyUmbrella a short while ago, but now there’s another way to do it courtesy of a Cydia app called iSHSHit.
Although the name may look like some crazy cursing, it will keep you from doing just that. Here’s why:
In a nutshell, an SHSH blob (or ECID SHSH) is like a unique identity that Apple tags every device with. Whenever you restore or upgrade your software, it’s used for authentication, and then Apple replaces it with a new blob.
This is the big reason everyone emphasizes saving your blob: If you ever have to restore, without a saved SHSH blob, you will be updated to the latest Apple firmware (whether there’s a jailbreak for it or not).
But if your blob is backed up, you can re-install/downgrade to your old firmware and then re-jailbreak it, if you want. So it’s like a safety net to preserve your jailbreak. (And some tweets from Comex indicate that it may also be required for future untethered jailbreaks.)
The new tool for saving those blobs, iSHSHit, is more than just a saucy name. Unlike TinyUmbrella, which requires desktop software to work, this can back-up your ECID SHSH right off your device to the Cydia servers (using the Cydia On File service), while giving you the ability to send blobs to yourself via email. And that’s a good thing. When it comes to data back-up, redundancy is key.
Best part is that iSHSHit couldn’t be easier to use. To start, just search Cydia for it and install it.
Then go back out to your homescreen, launch the app and then tap the Save button. That’s it! It takes a mere moment for your SHSH blob to be sent to Cydia for back-up. To email it, hit the Manage SHSH option…
Then tap the ID that comes up:
An email open for writing will pop up with your blob already attached, ready for you to address and send.
While TinyUmbrella did get updated recently for 4.2.1, there’s little reason to use it with iSHSHit around. The most attractive part of TinyUmbrella was how it preserved older basebands (for unlocking) even with newer Apple firmware on board. Unfortunately, says the developer, that capability has seriously gotten limited now:
Do not update to 4.2.1 for the baseband protection. TinyUmbrella is no longer able to kick you out of recovery for that version. TinyUmbrella still works for prior versions and will be able to restore and kick you out of recovery for those versions but 4.2.1 has a baseband version check that will stop your device from booting if your baseband was not updated.
So if you’re still considering using TinyUmbrella, be warned.
As for iSHSHit, let us know if you gave it a shot and how you like it.