Using Supercomputers to Crack Passwords
I had a system like this some time ago when I used to crack encryption keys. This comprised 24 processors (Pentium III class, as they were faster than Pentium IV for this particular problem). One central unit was used to control the cluster. The nodes and cluster were connected through a 24 port switch. The nodes comprised separate PCs running Mandrake Linux, with Samba taking care of the networking. Specialised software looked after the decryption, dividing the search space into blocks. The major problem was the amount of heat generated by running commodity boxes at 99% CPU load for extended periods of time – up to 18 hours per 40 bit key.
Now, it is possible to build far quicker systems. For the Word / Excel encryption key cracking problem, this can now be done in around 3 seconds, using precomputed keys and specialised hardware. However for password cracking, there is still no substitute for parallel processing to try all the possible combinations.
Another approach is not quite a supercomputer, but instead uses FPGA (field programmable gate arrays). This means that the search can be accelerated by “writing” the time consuming part (the decryption algorithm) in hardware (logical gates on a chip) rather than using software running on a general purpose CPU. At this point, I am not aware of this being used commercially. I did attempt to commission such a system, but found it difficult and costly to get the FPGA built.
The next step in the evolution of supercomputers for password recovery is not dissimilar to the FPGA approach, and uses GPU cores. These are the chips used to render graphics – since they are specialised, they outperform ordinary CPUs. NVidia has released the Tesla Personal Supercomputer, which comprises 960 cores utilising the CUDA parallel computing architecture. It weighs in at around 250 times the performance of a PC, whilst being in a PC sized case and not requiring special infrastructure (it draws about 1.3 KW of power).
Elcomsoft has already released high end password cracking software that uses the Tesla system. This is definitely the way of the future. The problem can be divided up over the available cores, providing a quick result. For Office 2007 files, there is no real shortcut, and the only solution is to search for passwords against the slow AES algorithm. In this case, a supercomputer like the Tesla system is what you need.
I believe that the NSA, the US Government agency that handles data security and encryption is currently using early quantum computers to break encryption. Quantum computers use some of the strange affects of quantum physics which readily supports parallel processing.
When this military technology filters down and is practical for ordinary use, we will see a massive leap forward in password recovery technology, since any password will be able to be quickly recovered, and any encryption key found, but until then we have the GPU based systems, and to a lesser degree clusters, as the most practical desktop supercomputer solution for password recovery.
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Tags: password recovery, supercomputer