Ticket #1120 (closed enhancement: fixed)

Opened 6 years ago

Last modified 6 years ago

[with patch] speed up point counting for elliptic curves over GF(p^n) if coefficients are in GF(p)

Reported by: malb Owned by: was
Priority: minor Milestone: sage-2.8.13
Component: number theory Keywords:
Cc: Work issues:
Report Upstream: Reviewers:
Authors: Merged in:
Dependencies: Stopgaps:

Description

If possible #E is computed over the prime subfield now. 

sage: EllipticCurve(GF(4,'a'),[1,2,3,4,5]).cardinality()
8
sage: k.<a> = GF(3^3)
sage: l = [a^2 + 1, 2*a^2 + 2*a + 1, a^2 + a + 1, 2, 2*a]
sage: EllipticCurve(k,l).cardinality()
WARNING: Using very very stupid algorithm for counting
points over non-prime finite field. Please rewrite.
See the file ell_finite_field.py.
29

sage: l = [1, 1, 0, 2, 0]
sage: EllipticCurve(k,l).cardinality()
38

Attachments

ell_finite_field_order.patch Download (8.4 KB) - added by malb 6 years ago.

Change History

Changed 6 years ago by malb

comment:1 Changed 6 years ago by mabshoff

  • Milestone changed from sage-2.9 to sage-2.8.13

comment:2 Changed 6 years ago by robertwb

Works great for me.

comment:3 Changed 6 years ago by mabshoff

  • Status changed from new to closed
  • Resolution set to fixed

Merged in 2.8.13.alpha1

Applied with slight fuzz: 

mabshoff@sage:$hg import ell_finite_field_order.patch
applying ell_finite_field_order.patch
patching file sage/schemes/elliptic_curves/ell_finite_field.py
Hunk #4 succeeded at 330 with fuzz 1 (offset 0 lines).

Cheers,

Michael

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