What is jailbreak and process behind it?


IOS users are thinking about jailbreaking word often when they heard about it. You may not aware that you’ve jailbroken your device. In this article I am going to discuss what it is actually, how it process and effects.

What is jailbreaking?

Generally iOS users install apps from apple App Store or iTunes Store. Jailbreaking processed iOS devices (iPhone, iPad and iPod touch) have ability to download and install apps which haven’t approved by Apple, such device shows an icon “Cydia” to install any third party iOS apps.

Generally we do jailbreaking by computer screen, plugin device into the computer, clicking a button, waiting a few minute, and jailbreak done but it’s little more complex in reality.

cydia icon


We must understand the boot sequence of iOS devices before jailbreak process. It’s basically a chain of trust which execute step by step. Apple verifies different level of security and signature checks to ensure that your hardware and software is certified by Apple during boot process. Boot sequence follows below order: BootROM, BootLoader, Kernel, and iOS operating system.

The process takes control of root and media partition of the device where all iOS files are stored. “private/etc/fstab” must be patched in order to control of root and media partition. FSTab controls the permissions of the device’s root and media partition. It’s difficult because of getting it done through certain checkpoints. Apple makes a checkpoint to verify FSTab either its standard or from a third party. The file is verified by a digital signature or key, the file is useless without it.

FSTab = File System Table (Control Device Permission)
Default = Read-Only (Default security is read only so you can view only and can’t modify)
We need to change it Default = Read-Write

Files and software signature verification is the major break in the jailbreak process and stop it. Tons of digital signatures and keys are verified when kernel load in the boot process to ensure everything is valid. If anything Apple found any invalid verification, your system will be crashed. Jailbreak work process can be done by either patch the checks or skip them. This brings us two categories.

BootROM Exploit. BootROM is the first process before any checkpoint and can’t be patched by a normal update. By putting synchronized code creates the gateway to bypass all signature checks or simply disable them. This can be done by new hardware only; it can’t be patched by any software updates. It’s easier and save your time from high secure kernel files coding.

Userland Exploit. By put modified code at the beginning and back into the kernel we can easily be patched by apple because it’s after all test. That’s happened during or after the execution of the kernel in boot process.

You can download several stunning iOS app such as gba4ios emulator, Popcorn time, Hipstore, Vshare without jailbreak. If your iOS device’s company warranty is expired or you don’t care Apple warranty then must try out jailbreaking for more iOS features. Apple void hardware and software warranty for jailbroken device because they want to control user experience, although it’s totally legal. Simplicity is one more reason for warranty limitation, they don’t want people to customize their system, hack the device and bad user experience.  

5/5 - (2 votes)

Related posts