If Apple is still "signing" that version (usually only the newest version), they send back a unique signature (the blob).
Every single iOS device possesses a unique hardware identifier called an (Exclusive Chip ID). When you attempt to install or restore iOS on your device, Apple combines your unique ECID with the specific iOS version details to generate a cryptographic token. This token acts as a digital "thumbs-up," allowing the installation process to proceed.
You save the signature to your hard drive. Later, when Apple stops signing the old version, you can trick your phone into thinking Apple said "Yes" by feeding it the saved blob.
: Modern-day lanterns used to capture and store these digital keys for later. The Cat-and-Mouse Game How to save SHSH Blobs ios 15 | by Telegram Bot shsh blobs
Even if you aren't planning to jailbreak today, saving blobs is a "better safe than sorry" practice.
Always use --latest-sep and --latest-baseband flags in FutureRestore. This pulls the newest signed SEP. It usually defeats the purpose of downgrading (because you end up with a mismatch), but it prevents a brick.
If you are looking to manage your device versions or check which firmware versions are still open for signatures, you can verify real-time windows using the IPSW Downloads Matrix, which keeps an updated log of every device and firmware configuration. To help me give you the most relevant advice, let me know: What are you using? What iOS version is your device currently running? If Apple is still "signing" that version (usually
This is where SHSH blobs enter the picture. They are the closest thing the iOS world has to a time machine. This article will explain what they are, how they work, why Apple hates them, and why they have become harder to use than ever before.
The device verifies this signature and proceeds with the installation.
However, modern iOS downgrades involve an additional complication: the . The SEP manages critical security tasks like Touch ID, Face ID, and device passcodes. It runs its own isolated firmware, which must also be signed by Apple during the restore process. This token acts as a digital "thumbs-up," allowing
Find your device's and Internal Name (Identifier) by plugging your device into a computer and using a tool like Finder, iTunes, or 3uTools. Visit the website: ://1conan.com . Input your ECID, select your device type, and click submit.
When a new iOS version patches a major vulnerability, Apple quickly stops signing the older version. This prevents users from downgrading to a vulnerable firmware version.
Saving blobs allows you to "fake" Apple's permission to restore to a firmware version that Apple is no longer signing. 1. Downgrading iOS
When you use a community tool like to downgrade your iOS version using your saved SHSH blobs, the tool must also source a SEP firmware package. The catch? The SEP firmware must be cryptographically signed by Apple at that exact moment .
Find your device's . You can find this by plugging your phone into a computer, opening iTunes/Finder, and clicking on the serial number field until it changes to reveal the ECID. Copy the hexadecimal ECID string. Visit the online TSS Saver portal.