Earlier today MuscleNerd tweeted the Jailbreaking Community a very important reminder – You can no longer Save SHSH blobs on the iOS 5 firmware or downgrade on the iOS 5 firmware.
If you remember correctly, back when Apple released some of the first beta firmwares for the iOS 5 firmware generation, we told you that you would no longer be able to save your SHSH blobs. This is because Apple has changed the role that *APTickets play on your iPhone, iPod Touch or iPad. This means you will no longer be able to restore your iPhone, iPod Touch or iPad to a lower firmware version once it is running the official iOS 5 firmware.
*APTickets are the main component used in saving SHSH blobs.
While there is no way to restore to a previous firmware once running the official iOS 5 firmware, the Dev-Team have made a couple of points which you should pay attention to:
- Restoring to pre-5.0 firmwares with saved blobs will still be possible (but you’ll soon start to need to use older iTunes versions for that).
- Geohot’s limera1n exploit occurs before any of this new checking is done, so tethered jailbreaks will still always be possible for devices where limera1n applies.
If you are thinking about updating to the iOS 5 firmware or already have this is something you will need to keep in mind.