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galois.is_irreducible(poly) seems to return some false negatives in large odd exponent GFs

See original GitHub issue

Hi Matt, hope all is well.

Even though it works fine for other groups (e.g. even groups likes GF(2^256) work well), still I 've been getting the following false negative result when using the galois.is_irreducible(poly) over odd groups tο produce irreducible polynomials over GF(2^233).

For example, we know from previous publications and research that x^233+x^74+1 is irreducible over GF(2) for creating the quotient ring of GF(2^233) but the following code returns Null for every polynomial (including the aforementioned one):

def loop_init_trinomial():
    #initial detection loop
    for k in range(1, 233):
        poly = galois.Poly.Degrees([233, k, 0])
        if galois.is_irreducible(poly):
            print("Found one: ", k, poly, poly.string)

Care to share some thoughts?

Issue Analytics

  • State:closed
  • Created a year ago
  • Comments:8 (5 by maintainers)

github_iconTop GitHub Comments

1reaction
mhostettercommented, May 16, 2022

And to be clear, I was incorrect about prime exponents. That wasn’t the issue. The issue was large exponents (that were secretly np.int64). I believe this bug was introduced after the refactor and major speed-ups from v0.0.26.

Again, I appreciate the bug report! 🙏

0reactions
geostergiopcommented, May 16, 2022

Yep sorry, bad reference!

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