How to Downgrade iOS 10.3 to iOS 10.2 with Future Restore

We have some good news for you today! Downgrading iOS 10.3 to iOS 10.2 is now possible without jailbreak. Let’s find out more about this method.

Here’s what we will be doing now – updating to 10.3 beta 1 and then using SHSH blobs to downgrade to iOS 10.2. Here’s a confirmation by Tihmstar, developer of Future Restore tool.

It only works for the iPhone 5S and iPad Air by abusing nonce collisions. This method will not work for newer devices as they patched nonce collisions.

prometheus downgrade ios 10

If you have a jailbroken iOS 9 device, there’s no point in trying this method. Upgrade straight away to 10.2 firmware with Prometheus. If you are feeling a little adventurous and meet all the requirements, give this method a go.

Before you begin, here are some things to keep in mind –

  • This method will not work if TSS Saver did NOT save SHSH blobs correctly. If you do NOT have an SHSH blob for 9e4c518009d00df190a450b3b47691768812360c, this method will not work for you.
  • Before you proceed, follow Prometheus Errors FAQ first.
  • This process can also be to upgrade iOS 9 to iOS 10.2 and downgrade iOS 10.3 to iOS 10.2.
  • If you are on iOS 9.3.3, there’s no point in upgrading as 9.3.3 is pretty good. However, you can still use this method.
  • This method is only recommended if you are on 9.3.4, 9.3.5, 10.2.1 and want to get to 10.2.
  • You can use a windows PC to restore your device to 10.3 beta 1 but then you will need to run Linux on Virtual Box to perform nonce collision OR you can just use VM Mac altogether. However, you cannot use windows, as is. You will need to use virtual box in some way.


  • iPhone 5S or iPad Air
  • A laptop/desktop running macOS with XCode
  • Internet Connection
  • SHSH Blobs for iOS 10.2
  • Download Future Restore tool
  • Download Noncestatistics
  • Download iOS 10.2.1 firmware for your device
  • Download iOS 10.2 Firmware for your device

You should now have the following files ready. Create a new folder called “Downgrade” in C drive and put these files in there.


How to Downgrade iOS 10.3 to iOS 10.2 with Future Restore [TUTORIAL]

Step 1 Update your device to iOS 10.3 beta 1 firmware with iTunes. Press SHIFT and click on Update at the same time and select your desired IPSW file.

Step 2 Return to the Downgrade folder and rename 10.2.1 IPSW to .rar. Open the RAR package and extract 3 these files given below.

  • Buildmanifest.plist
  • \Firmware\Mav7Mav8-7.21.00.Release.plist
  • Firmware\all_flash\all_flash.n53ap.production\sep-firmware.n53.RELEASE.im4p


Step 3 Open CMD (cmd.exe) on Windows or Terminal on Mac. Now type the following commands as shown below.

/noncestatistics nonce.txt


Step 3 Your device will now enter recovery mode and reboot many times. Wait and let noncestatistics do its thing. When you get 1000 apnonces, type CTRL+C and then type the command given below.

./noncestatistics –s nonce.txt


This command will output the frequency of all the nonces in an organized format. You will now get a screen similar to this.


Step 4 Open the folder containing your SHSH blobs and make sure the blobs with the highest frequency are present there. Select any one of them.


Step 5 Copy your chosen .shsh file in the Downgrade folder we created earlier.

Step 6 Delete all the items that are selected in the image below.


Step 7 Move futurerestore_macos to the Downgrade folder and delete futurerestore-latest folder to get this.


Step 8 Move the Downgrade folder in a USB drive or shared hard disk to your virtual machine or Mac OS.

Step 9 Move the Downgrade folder to the desktop.

Step 10 Connect your iOS device to the computer.

Step 11 We will now install Homebrew in Terminal. Enter the following commands as shown below.

/usr/bin/ruby -e “$(curl -fsSL”
brew install libplist
brew install libzip
cd desktop
cd downgrade
./futurerestore -t 8197106317392_iPhone6,2_n53ap_10.2-14C92.shsh -b
Mav7Mav8-7.21.00.Release.bbfw -p BuildManifest.plist -s sep-firmware.n53.RELEASE.im4p –
m BuildManifest.plist -w iPhone_4.0_64bit_10.2_14C92_Restore.ipsw

iphone 5s nonce collision-min

Step 8 Jailbreak iOS 10.2 firmware using our tutorial here.

This method is a godsend for those who are stuck on unjailbreakable firmware and want to enjoy the jailbreak. I hope this worked for you.

If you face any errors or problems, post them in the comments section below.


  1. LongNguyen April 10, 2017
    • Luca April 10, 2017
  2. blobb March 7, 2017
    • Luca March 7, 2017

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