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Open Source Attempt To Crack GSM Encryption

Posted by timothy on from the phone-you-break-could-be-your-own dept.

Lexta writes with an interesting tidbit from IEEE Spectrum: "'Karsten Nohl, chief research scientist with H4RDW4RE, a Sunnyvale, Calif.-based security research firm, is mounting what could be the most ambitious attempt yet to compromise the GSM phone system.' The intended approach is to create an open source project to spread the computation of a giant look-up table across more than 80 machines. Interestingly, they've openly stated that nVidia's CUDA technology will be used to execute parallel elements of the problem on GPUs as well."

1 of 78 comments (clear)

  1. Re:A big book by Anonymous Coward · · Score: 5, Informative

    TFA:

    The A5/1 cracking project aims to compress the 128-petabyte A5/1 codebook -- which would require more than 100 000 years of computing by a single PC to crack--to around 2 or 3 terabytes of data, and a computing time of around three months, with the help of about 80 computers.

    Any crypto experts want to take a stab at explaining, in lay geek terms, how this is even remotely possible? That's a ~50,000:1 compression ratio.

    Trading space for time.

    128 petabytes would enable instant lookup of collisions. Cutting size in half, and you'd need 2 operations to find a collision. Cut size in half again would need to double the time again. Repeat until you reach the desired space/time trade-off.

    P.C. van Oorschot, M.J. Wiener. Improving meet-in-the-middle attacks by orders of magnitude, Crypto'96, Springer LNCS vol.1109, pp.229-236, 1996. ps, pdf. A more complete treatment is given in the 1999 Journal of Cryptology paper.

    P.C. van Oorschot, M.J. Wiener. Parallel collision search with applications to hash functions and discrete logarithms. pp.210-218, proceedings, 2nd ACM Conference on Computer and Communications Security, Nov. 1994, Fairfax, Virginia. ps, pdf. The Crypto'96 paper builds on this, and a more complete treatment is in the 1999 Journal of Cryptology paper.

    P.C. van Oorschot, M.J. Wiener. Parallel collision search with cryptanalytic applications. Journal of Cryptology, vol.12 no.1 (Jan. 1999) pp.1-28. pdf.