diff --git a/src/gf256.py b/src/gf256.py
--- a/src/gf256.py
+++ b/src/gf256.py
@@ -23,7 +23,7 @@ for i in range(256):
 	L[acc] = i
 	acc = _gfmul(acc, g)
 L[1] = 0
-inv = [E[255-L[i]] if i != 0 else None for i in range(256)]  # multiplicative inverse
+INV = [E[255-L[i]] if i!=0 else None for i in range(256)]  # multiplicative inverse
 
 
 def gfmul(a, b):
@@ -40,14 +40,14 @@ def evaluate(coefs, x):
 
 	:param coefs: [a0, a1, ...]."""
 	res = 0
-	xK = 1
+	xk = 1
 	for a in coefs:
-		res ^= gfmul(a, xK)
-		xK = gfmul(xK, x)
+		res ^= gfmul(a, xk)
+		xk = gfmul(xk, x)
 	return res
 
 
-def getConstantCoef(*points):
+def get_constant_coef(*points):
 	"""Compute constant polynomial coefficient given the points.
 
 	See https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing#Computationally_Efficient_Approach"""
@@ -59,6 +59,6 @@ def getConstantCoef(*points):
 		for j in range(k):
 			if i==j: continue
 			(xj, yj) = points[j]
-			prod = gfmul(prod, (gfmul(xj, inv[xj^x])))
+			prod = gfmul(prod, (gfmul(xj, INV[xj^x])))
 		res ^= gfmul(y, prod)
 	return res