Re: CRC32 vd MD5

From: Aaron Cheek (aaron_cheekat_private)
Date: Sat Jan 04 2003 - 14:40:22 PST

  • Next message: John Howie: "RE: CRC32 vd MD5"

    When calculating a hash of a file for ensuring the
    authenticity of the evidence, we talk about the
    possibility of "hash collision", ie, of artificially
    creating a new file with the same signature than the
    original.
    
    With CRC32 (32-bit) it would only take 2^16 operations
    to get a hash collision by brute force, while with MD5
    (128-bit) it would take 2^64 ops.
    
    2^16 operations is a really small number, that's why
    it's considered trivial to "break".
    
    So the conclusion is that CRC32 should not be used for
    hashing evidence.
    
    Aaron
    
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