However, this also means that if a new iOS update degrades your battery life or introduces bugs, you are permanently trapped on that version once the signing window closes—unless you saved your blobs ahead of time. How Blobs Allow iOS Downgrades
He spent the night extracting. The white blob contained the first photo he’d ever taken on that phone—a blurry shot of a rain-spattered window. The purple blob held a text argument with his brother, the one they’d made up from two days later—the hash preserved the raw emotion of the fight, even if the words were gone. The green blob was the strangest: it contained a three-second recording of his own laughter from a forgotten voice memo, a laugh he no longer recognized as his own.
If you're an iOS user, you've probably heard of SHSH blobs, but maybe you're not entirely sure what they are or how they work. In this article, we'll take a deep dive into the world of SHSH blobs, exploring what they are, how they're used, and why they're so important for iOS enthusiasts.
The community has built powerful, user-friendly tools to make this automated. 1. TTS Saver (Web-Based) shsh blobs
When Apple stops signing an older version, that "window" closes. A device will only allow the OS installation if the response to the request is signed by Apple.
SHSH blobs are the cornerstone of and preserving a version of iOS that is jailbreakable .
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Help you being signed for your device Let me know how you'd like to proceed ! Device features and functions - ScienceDirect.com
To kill this exploit, Apple introduced a (a random, single-use number) into the handshake. Now, during a restore, the device generates a brand-new random nonce. The SHSH blob returned by Apple must match that exact nonce. Because the nonce changes every time, old cached blobs generally cannot be replayed directly unless the device can be forced to generate the specific matching nonce (a process known as nonce-setting, which requires a jailbroken state or an exploit). The Concept of the "Signing Window"
, you can use tools like to get there, even after the signing window closes. How to Save SHSH Blobs The purple blob held a text argument with
If you try to downgrade to iOS 14 using blobs, but the latest signed SEP is from iOS 17, the restore will fail. Your iPhone will bootloop because the old OS cannot talk to the new, incompatible security chip.
Beginning with devices using an , Apple introduced nonce entanglement . This security measure means that when saving SHSH blobs, a nonce generator produces a different APNonce for each device. For these devices, you must find a generator-APNonce pair for your device and reuse that pair whenever saving SHSH blobs.
You need a jailbreak to set the nonce to use the blobs you saved to get a jailbreak.