Apple did include a chip for hardware-based encryption on the 3GS, while iOS 4 saw 256-bit encryption thrown into the mix. The Russian forensic experts mentioned managed to circumvent both the on-device data protection and the backup file encryption, and here is what Vladimir Katlov (part of the crack team at ElcomSoft) has to say :-
“Decryption is not possible without having access to the actual device because we need to obtain the encryption keys that are stored in (or computed by) the device and are not dumped or stored during typical physical acquisition.”
To put it plainly, you will first need to retrieve ’s backups from their computer – and that alone is just half the solution when it comes to properly cracking iOS 4. Not only that, you will still need to “steal”, so to speak, someone’s iPhone to obtain relevant data.