diff --git a/src/shamira/benchmark.py b/src/shamira/benchmark.py
--- a/src/shamira/benchmark.py
+++ b/src/shamira/benchmark.py
@@ -21,7 +21,7 @@ def measure(args):
 def profile(args):
 	t = TestShamira()
 
-	cProfile.runctx(r"""t.test_generate_reconstruct()""", globals=globals(), locals=locals())
+	cProfile.runctx(r"""t.test_generate_reconstruct()""", globals=globals(), locals=locals(), sort="cumtime")
 
 
 def build_subparsers(parent):
diff --git a/src/shamira/fft.py b/src/shamira/fft.py
--- a/src/shamira/fft.py
+++ b/src/shamira/fft.py
@@ -1,6 +1,7 @@
 import math
 import cmath
 import itertools
+from functools import cache
 
 from .gf256 import gfmul, gfpow
 
@@ -20,6 +21,7 @@ def ceil_size(n):
 	return ni
 
 
+@cache
 def precompute_x(n):
 	"""Return a geometric sequence [1, w, w**2, ..., w**(n-1)], where w**n==1.
 	This can be done only for certain values of n."""
diff --git a/src/shamira/gf256.py b/src/shamira/gf256.py
--- a/src/shamira/gf256.py
+++ b/src/shamira/gf256.py
@@ -2,7 +2,7 @@
 
 """Arithmetic operations on Galois Field 2**8. See https://en.wikipedia.org/wiki/Finite_field_arithmetic"""
 
-from functools import reduce
+from functools import reduce, cache
 import operator
 
 
@@ -29,6 +29,7 @@ L[1] = 0
 INV = [E[255-L[i]] if i!=0 else None for i in range(256)]  # multiplicative inverse
 
 
+@cache
 def gfmul(a, b):
 	"""Fast multiplication. Basic multiplication is expensive. a*b==g**(log(a)+log(b))"""
 	assert 0<=a<=255, 0<=b<=255
@@ -38,6 +39,7 @@ def gfmul(a, b):
 	return E[t]
 
 
+@cache
 def gfpow(x, k):
 	"""Compute x**k."""
 	i = 1