18 Nov
2016
18 Nov
'16
11:22 p.m.
you might also look at patent 4979173
cirrus / adaptec from around that time
x^52 + x^50 + x^43 + x^41 + x^34 + x^30 + x^26 + x^24 + x^8 +1
licensed from Glover
On 11/18/16 3:02 PM, David Gesswein wrote:
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.…