National Semiconductor 48-bit and 56-bit ECC polynomials

[David Gesswein]

On Thu, Nov 17, 2016 at 03:33:36PM -0700, Eric Smith wrote:
> I'm not looking forward to trying to reverse-engineer 48-bit and 56-bit ECC
> polynomials. However, they usually tried to choose polynomials with
> relatively few terms, to minimize the number of XOR gates needed in the
> hardware.
> 
...
> There might be some other short-cuts to reducing the search space, but I
> haven't yet given it a lot of thought.
> 
> 
I haven't run across it yet. If they used it for the header it is easy to
reverse since they naturally have a pattern that is easy to calculate the
polynomial from. You may find sector data with the correct pattern to also 
use the method.

http://www.cosc.canterbury.ac.nz/greg.ewing/essays/CRC-Reverse-Engineering.html