With the release of Apple’s new iOS 5 this autumn (Fall for our American readers), jailbreakers might find jailbreaking more difficult than usual.
While iPhone Dev Team was examining the code for the iOS 5 beta 2, it was discovered that Apple is placing measures to make it harder for users who use iOS 5 to revert back to earlier versions of the iOS.
More advanced users usually try out the latest non-jailbroken version of the iOS and then downgrade to an earlier, jailbroken version, so they can take advantage of the features. The workaround users use is backing up the SHSH blobs before they upgrade the software. This move ensures that the older version of the iOS and its firmware can be restored afterwards.
With iOS 5, the company is changing the way blobs are created. The said blobs will be regenerated everytime users reboot their device, which means that having an older version won’t enable users to install the older version they have backed up.
This does not prevent the Dev Team from providing tools and finding ways to jailbreak the devices, it will just make it more difficult for them to keep the device in a jailbroken state.
With the new iOS 5, Apple is reported to be doing over-the-air OS upgrades, which means that updates can be done without connecting the device with iTunes. Apple then could push out tiny updates that prevents users from jailbreaking their devices.
On the Dev Team’s blog, they stated that “although there may still be ways to combat this, a beta period is really not the time or place to discuss them. We’re just letting you know what Apple has already done in their exisiting beta releases — they’ve stepped up their game!”