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iTunes Backup Passwords 'Much Easier' to Crack in iOS 10, Apple Working on Fix

iOS 10 uses a new password verification mechanism for iTunes backups that makes them easier to crack, according to testing performed by Elcomsoft, a company that specializes in software designed to access iPhone data.

Encrypted iTunes backups created on a Mac or PC are protected by a password that can potentially be brute forced by password cracking software. The backup method in iOS 10 "skips certain security checks," allowing Elcomsoft to try backup passwords "approximately 2500 times faster" compared to iOS 9 and earlier operating systems.

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Obtaining the password for an iTunes backup provides access to all data on the phone, including that stored in Keychain, which holds all of a user's passwords and other sensitive information.
At this time, we have an early implementation featuring CPU-only recovery. The new security check is approximately 2,500 times weaker compared to the old one that was used in iOS 9 backups. At this time, we are getting these speeds:

iOS 9 (CPU): 2,400 passwords per second (Intel i5)
iOS 9 (GPU): 150,000 passwords per second (NVIDIA GTX 1080)
iOS 10 (CPU): 6,000,000 passwords per second (Intel i5)
In specific terms, security analyst Per Thorsheim of Peerlyst says Apple has switched from using a PBKDF2 hashing algorithm with 10,000 iterations to using a SHA256 algorithm with a single iteration, allowing for a significant speed increase when brute forcing a password.

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Image via Peerlyst

In a statement given to Forbes, Apple confirmed it is aware of the issue and is working on a fix.
"We're aware of an issue that affects the encryption strength for backups of devices on iOS 10 when backing up to iTunes on the Mac or PC. We are addressing this issue in an upcoming security update. This does not affect iCloud backups," a spokesperson said. "We recommend users ensure their Mac or PC are protected with strong passwords and can only be accessed by authorized users. Additional security is also available with FileVault whole disk encryption."
As Apple points out, this security oversight is limited to backups created on a Mac or PC and does not affect the security of iCloud backups. Most users likely do not need to worry about this issue as it requires access to the Mac or PC that was used to make the backup.

Apple has updates for iOS 10 and macOS Sierra in the works, and it's possible a fix will be included in the new versions of the software. iOS 10.1 and macOS Sierra 10.12.1 were seeded to developers and public beta testers earlier this week.

Related Roundup: iOS 10


Top Rated Comments

(View all)

21 weeks ago
Physical access to ANY machine is a security risk, no matter how strong password encryption is.
Rating: 20 Votes
21 weeks ago
I love Apple, but this sort of thing is so frustrating from a company that is trying to make privacy be such a huge part of its brand. Without security, privacy cannot exist. It doesn't have a huge effect on me, but it lowers my level of trust that Apple knows what it's doing.

As a developer, this is a pretty glaring flaw, so I can only assume (or hope, rather) it was a temporary implementation that accidentally got through to a release version. Whatever happened, it's bizarre.
Rating: 17 Votes
21 weeks ago
They must hurry up. Yahoo was lucky enough their stocks were already worth nothing before the hacking.
Rating: 17 Votes
21 weeks ago
Pretty lazy on their part.
Rating: 13 Votes
21 weeks ago

But this is NOT physical access to the iPhone. They are talking about decrypting the BACKUP data. This data is typically on e hard drive on a PC or Mac or maybe in Apple's iCloud

This is iTunes backups. Most don't use iTunes backups these days, even fewer would have had time to make one for iOS 10. While this doesn't demand physical access to an iPhone, it seems to me like it would demand physical access to a PC or Mac (and only a PC or Mac, not an iPhone or iPad).
Rating: 12 Votes
21 weeks ago
Lowered security threshold because hacking is becoming less of an issue in 2016...?
Rating: 12 Votes
21 weeks ago

Doesn't matter...


https://www.elcomsoft.com/products.html


Did you not read the description of what is required?

Decrypt FileVault 2 Volumes

FileVault 2 is a whole-disk encryption scheme used in Apple’s Mac OS X. FileVault 2 protects the entire startup partition with secure 256-bit XTS-AES encryption.

If the user forgets their account password, or if the encrypted volume is moved to a different computer, a FileVault 2 can be unlocked with a special Recovery Key. If the user logs in with their Apple ID credentials, the Recovery Key can be saved into the user’s iCloud account. Should the user forget their password, the system can automatically use the Recovery Key to unlock the encrypted volume. It is important to note that Apple does not allow the end user to view or extract FileVault 2 recovery keys from iCloud.

Elcomsoft Phone Breaker can extract FileVault 2 recovery keys from the user’s iCloud account, and use these keys to decrypt encrypted disk images. Valid authentication credentials (Apple ID/password or iCloud authentication token) as well as volume identification information extracted from the FileVault-encrypted disk image are required.
Rating: 11 Votes
21 weeks ago

I'd imagine this was a big mistake by one of their developers. They should have more code reviews.


There was no reason to suddenly change the encryption mechanism, except to make it easer to crack.
Rating: 10 Votes
21 weeks ago

Physical access to ANY machine is a security risk, no matter how strong password encryption is.


But this is NOT physical access to the iPhone. They are talking about decrypting the BACKUP data. This data is typically on e hard drive on a PC or Mac or maybe in Apple's iCloud
Rating: 10 Votes
21 weeks ago
According to security.stackexchange.com, this is a huge mistake:
http://security.stackexchange.com/questions/16354/whats-the-advantage-of-using-pbkdf2-vs-sha256-to-generate-an-aes-encryption-key#16357

PBKDF2 is an intentionally slow algorithm, meant to make brute force guessing of passwords difficult.
SHA256 is a very fast algorithm, meant to produce hashes for dictionaries and sets and whatnot - basically, it helps make all your programs run quickly.

Normally quicker is better, so SHA256 is preferable in almost all situations, except when it comes to storing your password.

Either someone made an honest mistake and thought, hey, lets make this run faster because faster is better and they didn't consider the implications of hacking being faster, or they intentionally wanted to cripple security.
Rating: 8 Votes

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