On Mar 7, 7:09 pm, Gregory Ewing <greg.ew...@canterbury.ac.nz> wrote: > Given some known data/crc pairs, how feasible is it to > figure out the polynomial being used to generate the crc? > > In the case I'm looking at, it appears that the crc > size may be at least 24 bits, so just trying all possible > polynomials probably isn't doable. > > An article I found hints at the possibility of using > GCDs to make the search more efficient, but doesn't go > into any details. Anyone know of any literature about > this? > > If it helps, I have the ability to generate test cases > with known message contents to some extent, although > I don't have complete control over the contents. Also > it's a manual process, so generating large numbers of > them automatically isn't an option. >
Hi Greg. I would at least flip one bit at a time on the first byte of your data to see if the transformation is bitwise. -- http://mail.python.org/mailman/listinfo/python-list
