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And yet Apple still can't figure out how to prevent a website from allowing the device to be jailbroken.

They fixed that in iOS 4 already. Luckily, I hadn't updated at that point, so I was able to jailbreak my iPod touch with the swipe of a bar on jailbreakme.com.
 
Of course, but if we're talking pragmatically about truly unbreakable "systems", at the moment only the one-time pad is unbreakable.

In any other system it is mathematically probable that you can guess the key in your first attempt or first few attempts (although, yes, extremely unlikely). This is not the case with a one-time pad.

Yep, that's why I said it's technically possible. It's as easy as just guessing the key. ;)

But some fun math tells us if we do 14trillion calculations a second, it will still take us an unfathomable number of years to try 0.0000000001% of the possible keys. :D

That being said I have no concerns with aes encryption! Brute force away lol.
 
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*phone rings*

hi this is tom calling from apple. We noticed some recent activity on your itunes account potentially originating from your iphone and we need your iphone device passcode to verify whether or not these charges for $45,912 are fraudulent so we can refund your money.

...

lol :d
 
Also, the iOS passcode also lets you use some symbols and the space. There are 26 letters + 10 numbers + 15 symbols + 20 symbols (page 2) + space. You cannot use letters/numbers/symbols from other languages like Arabic or Chinese. There are 72 characters to choose from for each slot.

So 72^8 possibilities / 2 * 80ms = 2.888E16ms ~ 9.1541E5 years.... :confused:

Only letters and numbers: 36^8/2*80ms ~ 3575.8 years.... :confused:

Not sure if I made mistake or if they aren't using the same number of possibilities as I am. You divide the number of possible passcodes by 2 and multiply by 80ms to find the estimated cracking time, right?

Only numbers: 10^8/2*80ms ~ .1268 years.
Only letters: 26^8/2*80ms ~ 264.6932 years.
:confused::confused::confused::confused::confused::confused::confused:

The iteration count is calibrated so that one attempt takes approximately 80 milliseconds. This means it would take more than 5½ years to try all combinations of a six-character alphanumeric passcode with lowercase letters and numbers
Assuming the last password they try is the right one, it would take 36^6*80/1000/60/60/24/365 years to crack that, which is about 5.522 years. So my math is not off, and I am calculating the crack time for the other ones in a similar fashion except that I divide by 2. Why am I getting such huge numbers?
 
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Heard It Before

The algorithm is so strong that no computer imaginable for the foreseeable future—even a quantum computer—would be able to crack a truly random 256-bit AES key
OK I know this is supposed to be the ultimate but pardon me if I'm a little bit skeptical. I've heard the same refrain all the way back to the "unbreakable" 32 bit encryption in the last century. Someone will figure out a sneaky way to short circuit the decryption. Or computers will exceed anything "foreseeable" way ahead of schedule.

The only secure data is data that cannot be accessed.
 
Big deal. Most smartphones use encryption.

Not true. Blackberries, yes. Android, no, until 4.01 or later, as far as I know. Even then, it's optional. You have to perform additional steps to enable it.
 
Yes brute force will work eventually. But not only is it unrealistic, it's impossible given the computing powers of today's machine.

So while technically you could brute force an aes key, chances are the world will be over before you try even 1% of the possibilities lol.

Right and wrong.

Yes, with OTP, a brute force attack would eventually uncover the plaintext. However, the thing with OTP is that the return of the original plaintext is no more or less likely than the return of any other equivalent length string.

For example, of the plaintext is "The car was green," brute forcing an OTP cypher will eventually return "The car was green" but is equally likely to return "Our son has drugs", "Her dad has aids." "The PCP has moved" "The hit was done." or any one of countless, equally non-trivial phrases. This is in contrast to non-OTP cyphers where it's rather obvious that recovered plaintext that makes any kind of sense is probably a successful decryption.

This, probably more than anything, makes OTP, not worth the brute force. Coupling OTP with code phrases makes it even less worth the trouble because without the meaning of the code phrases, or even a list of code phrases, one has no idea if they've recovered a code phrase or just some other sentence.
 
Someone will figure out a sneaky way to short circuit the decryption.

Like stated, AES is now a 14 year old algorithm. If it was short circuitable, it would have been. Microsoft researchers have been able to find an attack in 2011 that reduces key recovery for AES-256 to a 2^254.4 operations affair.
 
Also, the iOS passcode also lets you use some symbols and the space. There are 26 letters + 10 numbers + 15 symbols + 20 symbols (page 2) + space. You cannot use letters/numbers/symbols from other languages like Arabic or Chinese. There are 72 characters to choose from for each slot.

So 72^8 possibilities / 2 * 80ms = 2.888E16ms ~ 9.1541E5 years.... :confused:
You are using exponents to start, which is incorrect. You need permutations to calculate the number of possible "words". So, n=number of possible characters, r=word length. Formula, with repeats of n possible:

(n+r-1)!
r!(n-1)!

So, for:
n=72
r=8
Answer:
~33 years, if I did everything right this fast. I could be wrong.

Or:
~15 years, if repeats not allowed. (different formula) So, I assume others have assumed no repeats of characters.
 
"The algorithm is so strong that no computer imaginable for the foreseeable future..."

Humans have a bad record of "imagining" what computers will be capable of doing. Also, what happens after the foreseeable future? Imagine that.

Maybe it's not our computers that will be of interest after the foreseeable future. ;)
 

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You are using exponents to start, which is incorrect. You need permutations to calculate the number of possible "words". So, n=number of possible characters, r=word length. Formula, with repeats of n possible:

(n+r-1)!
r!(n-1)!

So, for:
n=72
r=8
Answer:
~33 years, if I did everything right this fast. I could be wrong.

Or:
~15 years, if repeats not allowed. (different formula) So, I assume others have assumed no repeats of characters.

That formula is not allowing repeats. You use exponents for permutations with repeats allowed. A snapshot from that site:
perm.png


And what I did worked for the 6-digit numbers-only calculation that Apple gave out. I DID forget about capital letters, though, but I get wrong answers even with that.
 
Couldn't have said it better myself!

Yes, 256 AES is nearly impossible to crack in a timely fashion, that only addresses brute force attacks. The main weakness to encryption is humans-- through other programs installed on the systems which contain weaknesses (looking at you Adobe), not updating patches in a timely manner, phishing, and social engineering. No one needs to crack AES, they just need you, the user, to show your weakness-- a much simpler way to get what they want.

So update the grey fatty mass between your ears, and learn how to keep your 1's and 0's private. Also, hope that those who take care of your info are doing the same (looking at you Apple, Google, Microsoft, Sony, Chinese take-out receipts [credit card info], etc.)

It may just be easier to put your head between your legs and kiss your ass goodbye.

Sounds like a Mitnick quote! Although I can't agree more with what you're saying, the biggest threat to a computer system is the user itself!

Social engineering should be a focal point of any security plan in this day and age!
 
You can debate the mathematical details of encryption until the cows come home but in the Real World your garden-variety thief has neither the means nor the knowledge to crack encrypted devices and data.

So it's up to the user to use encryption and pass phrases that are difficult to guess. That is sufficient protection for the 99.999% of users who do not have to worry about the NSA attempting to decrypt their data.
 
That formula is not allowing repeats. You use exponents for permutations with repeats allowed. A snapshot from that site:


And what I did worked for the 6-digit numbers-only calculation that Apple gave out. I DID forget about capital letters, though, but I get wrong answers even with that.

Hmm, I didn't set "order important", that's where I screwed up. Maybe their calc was using some other set?

Ah, Apple's PDF only claimed 2 calcs:
The passcode is “tangled” with the device’s UID, so brute-force attempts must be
performed on the device under attack. A large iteration count is used to make each
attempt slower. The iteration count is calibrated so that one attempt takes approximately
80 milliseconds. This means it would take more than 5½ years to try all combinations
of a six-character alphanumeric passcode with lowercase letters and numbers, or
2½ years for a nine-digit passcode with numbers only.
The other may have been MR, and more likely to be in error.

Also, Apple says "all combinations", so remove your halfway "/2" calc. Then it works perfectly for me. I should clarify. Then Apple's two work for me. I can't get 15 years at all. Must have done some other sort of calc.
 
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I thought the device goes into permanent lock down requiring it to be wiped if the wrong password is used too many times. So how could you brute force the password?
They are probably assuming the memory is removed from the device, so the operating system is not running, hence unable to start the wipe process.

----------

The only secure data is data that cannot be accessed.
There must be a water boarding app for that. :)
 
You can debate the mathematical details of encryption until the cows come home but in the Real World your garden-variety thief has neither the means nor the knowledge to crack encrypted devices and data.
Plus, the govt will have the FBI at the phone's location in minutes. Cause you have to leave it turned on to hack it.
 
Like stated, AES is now a 14 year old algorithm. If it was short circuitable, it would have been. Microsoft researchers have been able to find an attack in 2011 that reduces key recovery for AES-256 to a 2^254.4 operations affair.

Lol yea I read that in conjunction with some android users thinking they'd be able to unlock moto bootloaders easier. Funny stuff.
 
I'm wondering...

Will this AES-256 feature be available on the next iPhone or is this something that will be implemented in the future?

Thanks.
 
"The algorithm is so strong that no computer imaginable for the foreseeable future—even a quantum computer—would be able to crack a truly random 256-bit AES key."

but quantum computers have near infinite processing power....
 
Will Apple phone tech support tell you your key if you give them your home address and last 4 digits of your credit card number?

Apple doesn't know what your 4-digit passcode is, so there's no way thay can tell you what it is.

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"The algorithm is so strong that no computer imaginable for the foreseeable future—even a quantum computer—would be able to crack a truly random 256-bit AES key."

but quantum computers have near infinite processing power....

Unless you have information on your iPhone worth enlisting the use of a quantum computer for several weeks or months, I wouldn't worry about it.
 
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