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Update hashtocurve.sage #5

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Update hashtocurve.sage #5

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12 changes: 6 additions & 6 deletions hashtocurve.sage
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
import sys
from math import ceil, log
from struct import pack
from pyblake2 import blake2b
from Cryptodome.Hash import BLAKE2b as blake2b
from hashlib import sha256

if sys.version_info[0] == 2:
Expand All @@ -27,7 +27,7 @@ OP_COUNT = False

# E: a short Weierstrass elliptic curve
def find_z_sswu(E):
(0, 0, 0, A, B) = E.a_invariants()
(_, _, _, A, B) = E.a_invariants()
F = E.base_field()

R.<x> = F[] # Polynomial ring over F
Expand Down Expand Up @@ -75,15 +75,15 @@ class ChudnovskyPoint:
z3 = z^3

if DEBUG:
(0, 0, 0, A, B) = E.a_invariants()
(_, _, _, A, B) = E.a_invariants()
assert z2 == z^2
assert z3 == z^3
assert y^2 == x^3 + A*x*z^4 + B*z^6

(self.x, self.y, self.z, self.z2, self.z3) = (x, y, z, z2, z3)

def add(self, other, E, c):
(0, 0, 0, A, B) = E.a_invariants()
(_, _, _, A, B) = E.a_invariants()

# Unified addition on y^2 = x^3 + Ax + B with Chudnovsky input and output.
(X1, Y1, Z1, Z1_2, Z1_3) = ( self.x, self.y, self.z, self.z2, self.z3)
Expand Down Expand Up @@ -209,7 +209,7 @@ def map_to_curve_simple_swu(F, E, Z, u, c):

# would be precomputed
h = F.g
(0, 0, 0, A, B) = E.a_invariants()
(_, _, _, A, B) = E.a_invariants()
mBdivA = -B / A
BdivZA = B / (Z * A)
Z2 = Z^2
Expand Down Expand Up @@ -428,7 +428,7 @@ def hex_bytes(bs):

def hash(hasher, msg):
if VERBOSE: print(hex_bytes(msg))
h = hasher()
h = hasher.new(digest_bits=512)
h.update(msg)
return h.digest()

Expand Down