Connect your device to your computer and open iTunes or Finder.
An automated bot that saves blobs for your devices.
Apple uses this system to enforce software homogeneity. By "unsigning" older versions of iOS shortly after a new update is released, Apple ensures that the vast majority of its user base is on the most recent, secure version of the software. For Apple, this minimizes fragmentation and closes security vulnerabilities. For the enthusiast community, however, this "signing window" is a cage. If a user accidentally updates to a version of iOS that cannot be jailbroken, or if a new update slows down an older device, they are traditionally unable to "downgrade" to a previous version because Apple is no longer issuing the necessary blobs. Saving Blobs: The Escape Hatch shsh blobs
Set the generator value on your device to match the generator string inside your blob file.
Because the blob contains your specific ECID, . You cannot use an SHSH blob saved from a friend’s iPhone to downgrade your own iPhone, even if they are the exact same model. Why You Should Save SHSH Blobs Connect your device to your computer and open
Think of it as a digital permission slip. When you install, update, or restore iOS on an iPhone, iPad, or iPod touch, your device sends a request to Apple. Part of this request includes its , a unique serial number hard-coded into its processor. Apple's server then checks the iOS version you're trying to install. If Apple is still officially "signing" that version, the server combines your ECID with the iOS version and your device model to generate a unique SHSH blob. This blob is then sent back to your device, authorizing the installation.
Without a valid blob for a specific version, Apple’s servers will reject the installation, effectively forcing you to stay on (or upgrade to) the latest "signed" version. Why They Matter: The Power of Downgrading By "unsigning" older versions of iOS shortly after
Download and install from its official GitHub repository. Connect your iOS device to your computer via USB.
The cat-and-mouse dynamic surrounding SHSH blobs illustrates a broader philosophical divide. From Apple’s perspective, preventing downgrades is a vital security measure. It ensures that all devices on a network run the latest patches, mitigating known exploits. For security researchers and jailbreak developers, however, the inability to downgrade hinders vulnerability analysis and legacy software preservation. SHSH blobs are thus a form of digital civil disobedience—a way for power users to reclaim agency over hardware they legally own.