You can now download Prometheus tool to downgrade or upgrade unsigned iOS firmware version with saved SHSH2 blobs.

Tihmstar, who happens to be the developer behind the tool, has also released detailed videos showing the step by step instructions on how to go about using his tool to downgrade or upgrade a compatible iPhone, iPad or iPod touch device running on an unsigned iOS firmware version.

shsh-blobs

Before you go ahead and check out those videos though, go through the following points to see what exactly you will need in order to make use of Prometheus.

  • You can use Prometheus only if you have SHSH2 blobs saved for the unsigned firmware you are downgrading or upgrading to.
  • If you don’t have SHSH2 blobs saved for the unsigned firmware you want to downgrade or upgrade to, you can no longer do so as Apple has closed the signing window.
  • If you want to save SHSH2 blobs for a firmware Apple is still signing, you can follow our instructions on how to do so here.
  • You can upgrade/downgrade 9.x to 9.x with SHSH2 blobs saved.
  • You can also upgrade/downgrade 10.x to 10.x as long as SHSH2 blobs are saved.
  • Upgrade from iOS 9.x to 10.x is also possible as long as SHSH2 blobs are saved.
  • Downgrade from iOS 10.x to 9.x is not possible.
  • There are two methods, one which requires jailbreak for the firmware you are upgrading or downgrading from, and the second method which doesn’t require jailbreak for the firmware you are upgrading or downgrading from. Details, limitations and instructions for both, jailbreak and non-jailbreak methods, can be seen in the videos embedded below.
  • Depending on the method you choose, you will be making use of futurerestore, nonceenabler and img4tool utilities, together they basically make up Prometheus as Prometheus itself doesn’t have any graphical interface of its own.
  • Prometheus works on 64-bit devices only. On iPhone 7/7 Plus it “may be iffy” at best.
  • Prometheus is available on Mac only at this time. Windows and Linux versions will be available later.

Now for instructions, as mentioned earlier, depending on whether you are already jailbroken or not, you will be making use of different Prometheus utilities and methods.

If you are currently jailbroken, and are upgrading or downgrading to a firmware with SHSH2 blobs saved, follow the instructions in the video embedded here:

If, however, you aren’t jailbroken, and are upgrading or downgrading to a firmware with SHSH2 blobs, then you need to follow the instruction in the video embedded below:

Prometheus in its current state has a lot of limitations and maybe confusing for a lot of users. But at least we have some progress now on unsigned firmware downgrading front. Hopefully, future revisions of Prometheus will reduce some of the limitations it has right now and will make it more user-friendly for everyday jailbreakers.

Prometheus, and set of its utilities, required for this can be downloaded from here.

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