A faster function to solve the DLP question in ecc's singular_curve.py

[ScH01ar]

In some tests, using "return v.log(u)" instead of "return int(discrete_log(v, u))" is more efficient. What are the differences between the two functions? Thanks.

[jvdsn]

Which tests are you referring to specifically? Those functions are heavily overloaded, and do different things depending on the type of the input parameters (finite field element, integer, real number...)

[ScH01ar]

such as this script

p=193387944202565886198256260591909756041 P. = GF(p)[] f = x^3 + 2*x^2 + x P = (4, 10) Q = (65639504587209705872811542111125696405, 125330437930804525313353306745824609665) print(f) f = f.subs(x=x-1) print(f) print (f.factor()) P = (P[0] +1, P[1]) Q_ = (Q[0] +1, Q[1])

t = GF(p)(193387944202565886198256260591909756040).squareroot() u = (P[1] + tP[0])/(P[1] - tP[0]) % p v = (Q[1] + tQ[0])/(Q[1] - tQ_[0]) % p print (v.log(u))

[jvdsn]

@ScH01ar could you link where this is used in the repository, I can't find it.

[ScH01ar]

attacks/ecc/singular_curve.py : line 43

[jvdsn]

I didn't see too much of a performance difference, but I replaced it anyway for consistency: https://github.com/jvdsn/crypto-attacks/commit/9af6ac20f0abe387a7dcd8c92dc286e997774a75 Thanks.