Bruteforcing 3des support!!

[CRGreathouse]

Originally Posted by t3st3r10

for 1 byte 256 combinations from 00 to FF, ok i know its triple des so its encrypted K1K2 dividing the 112bits key into 2 64 bits keys, as i know the hardware and software that was used and due to its CPU and software limits, and taking huge amounts of time encrypt and decrypt, the tool had to use the following encryption method using 2 keys of 64bits

If I understand correctly you're saying it's keyring 2 encrypted -- only two keys rather than 3. It's actually better than the 64+64 = 128 bits you'd expect, since DES was weakened to an effective 56 bits leaving you with just 112 bits of effective key to search. At one decryption per cycle it would take about 2^112 / 3e9 seconds or about 5 * 10^16 years to search the keyspace. But if you apply all the computing power on Earth that should give you another factor of 10^10 or so, reducing the time to maybe 5 million years.

[bsquared]

Originally Posted by CRGreathouse

If I understand correctly you're saying it's keyring 2 encrypted -- only two keys rather than 3. It's actually better than the 64+64 = 128 bits you'd expect, since DES was weakened to an effective 56 bits leaving you with just 112 bits of effective key to search. At one decryption per cycle it would take about 2^112 / 3e9 seconds or about 5 * 10^16 years to search the keyspace. But if you apply all the computing power on Earth that should give you another factor of 10^10 or so, reducing the time to maybe 5 million years.

Ah, but that's assuming you take the world's current stockpile of computers and plug then in in a corner somewhere and let them go. Future generations would be able to use their equipment for other things, like looking at pictures of cats or getting into arguments with strangers on the internet.

If instead we apply the entire world's computational infrastructure here and from now on to the task of recovering this key, we could do it in a few hundred years, depending on assumptions about how fast the world's computational infrastructure doubles in capability.

And if we put aside our petty human squabbles and dedicate the world's GDP to the task of building ever better computers and immediately harnessing them to this task, we could maybe have this key cracked within his lifetime!

[CRGreathouse]

Originally Posted by bsquared

Ah, but that's assuming you take the world's current stockpile of computers and plug then in in a corner somewhere and let them go. Future generations would be able to use their equipment for other things, like looking at pictures of cats or getting into arguments with strangers on the internet.

If instead we apply the entire world's computational infrastructure here and from now on to the task of recovering this key, we could do it in a few hundred years, depending on assumptions about how fast the world's computational infrastructure doubles in capability.

Yes, I'm assuming that we take the current world stock and run only this task, but don't devote new resources (other than electricity, etc.) to the task.

Originally Posted by bsquared

And if we put aside our petty human squabbles and dedicate the world's GDP to the task of building ever better computers and immediately harnessing them to this task, we could maybe have this key cracked within his lifetime!

I think we could definitely crack this within a lifetime, but probably not by building better computers alone. I think improvements in theory would have to carry to bulk of the weight, with software improvements and hardware advances making up the balance. Well, and maybe we could get another 2-3 orders of magnitude by overhauling the world economy to focus on building computing devices.