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Apple Has Stopped iOS Downgrading
An anonymous reader noted a forum post seems to confirmApple will be
fighting downgrading in iOS 5. Quoting:
"This will only affect restores starting at iOS5 and onward, and Apple will be able to flip that switch off and on at will (by opening or closing the APTicket signing window for that firmware, like they do for the BBTicket)."
You live by the wall, you die by the wall.
Disagreeing with me does not mean you get to mod me troll.
I found when I upgraded from iOS3 to iOS4 on my 1st gen iPad it caused it to work sluggishly. I was considering going back to iOS3 if possible and I'm even more afraid to go to iOS5. I got the iPad at xmas and not even 6 months in I felt I'm already behind in performance.
Three reasons, I suspect:
1. In most walled gardens with cryptographically secured clients(either hardware devices or software DRM piles on general purpose PCs) downgrading is a valuable tool for attackers: unless a fundamental attack is found, most attacks are comparatively minor bugs in version N or game Y's savegame loading routine or whatever, which are then fixed in version N+1 or game Y Gold Edition. If downgrading is possible, it becomes pretty trivial for people to keep a copy of the easiest-to-exploit firmware or software version that ever received a cryptographic signature, and then downgrade to it. If downgrading isn't possible, they have to keep finding fresh exploits as old holes are closed. This is the same reason why software that connects to DRMed media sources tends to get updated a zillion times a year, and why such updates are generally made mandatory pretty quickly.
2. At least some of the updates, for Apple's flagship devices(upon which the iPod touch and wifi-only iPad are sort of hangers-on), aren't just OS update lumps, they also meddle with the embedded cellular hardware's firmware. Allowing downgrading would require dealing with v.N+1 basebands talking to v.N OSes, or involve allowing the baseband firmware to be downgraded(which is of interest to unlockers and other parties who Apple's carrier buddies don't approve of) and may involve some amount of bricking risk.
3. Apple has, at least until shitstorms forced their hand, never been much troubled at the idea that they are seen as forcing people to upgrade(remember their original response to the iPod battery life problem, until whining forced them to change it? Or the various OS 10.x releases that have dropped support for hardware configs upon which, once the version check is hacked away, it can in fact run?). This seems to be a matter both of business and of philosophy: Obviously, as a hardware maker, anything that makes people buy new hardware is profitable. Philosophically, they have never shied away from a pattern of releases of the form "Here is version N+1, it is insanely great. Everything prior to today is an obsolete archaism. On the plus side, this allows them to do interesting things with some regularity. On the minus side, this makes them quite happy to declare various features dead well before some of their customers are ready. The idea that they would dedicate engineering effort to allowing people with version N-1 or N-2 devices to run an obsolete OS runs against their priorities.
Yes, better to use Android, where there are no restrictions on downgrading.
I assume this was sarcasm. But the difference, as I understand it, is that on Android, a user doesn't need to downgrade to a jailbreakable version just to install applications outside the scope of what the central app store's curator allows. All Android-powered phones support adb install, and most support "Unknown sources". Even AT&T has been turning "Unknown sources" back on due to popular demand for Amazon Appstore.