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Posted by JoeBloe on 01/05/07 01:38
On Thu, 4 Jan 2007 08:09:15 -0800, The Ghost In The Machine
<ewill@sirius.tg00suus7038.net> Gave us:
>In comp.os.linux.advocacy, Wayne McClaine
><gary.griffith@gmail.com>
> wrote
>on 3 Jan 2007 21:19:22 -0800
><1167887962.598432.130480@31g2000cwt.googlegroups.com>:
>>
>> Tim Smith wrote:
>>>
>>> This depends on what you mean by "broke". In particular, do you
>>> consider a successful brute force attack a break? With its mere 40-bit
>>> key length, and weak algorithms, CSS falls fairly quickly to a brute
>>> force attack, in about 2^25 steps.
>>
>> Any encrypted cipher can be "foiled" by brute force - you're just
>> looking for a key.
>
>2^40 = 1.10 trillion. If one can look at a key every microsecond, that
>only takes about a week and a half. That's about what it took a French
>compute farm, if memory serves.
>
>2^56 = 7.21 * 10^16. At the same key rate, that'll only take about 2.3
>millennia. Fortunately, distributed.net has a faster key rate, since
>the problem is inherently parallel.
>
>2^1024 = 1.80 * 10^100, or 1.80 googols. Search company, meet
>military-grade encryption-cipher. Dare I mention that the Universe is
>at the very very most 80 billion years old or so?
>
>>
>> When it is doable in a relatively short time, it's broken. Not
>> circumvented or broken "into", no magic bullet, but might as well be -
>> even if you can't derive the key, if you can run through all
>> possibilities, then what's the difference? You can get the key, and
>> systems built on this are houses-of-cards. Hence, AES, 3DES, etc.
>>
>> So, our boy got a PowerDVD software key to then expose the DVD title &
>> volume keys and such. And this is impossible for other players, how?
>> Yawn.
>>
>
>How big is the key?
>
The problem isn't the key or that you have a distributed app to
try keys. The problem is what do you try them on?
A .vob file?
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