Make comparing single runs of speed.py meaningful

speed.py

@@ -1,8 +1,10 @@
-import six
 import timeit
 from ecdsa.curves import curves
 
 
+UNIQUE_KEYS = 100
+
+
 def do(setup_statements, statement):
     # extracted from timeit.py
     t = timeit.Timer(stmt=statement, setup="\n".join(setup_statements))
@@ -12,7 +14,7 @@ def do(setup_statements, statement):
         x = t.timeit(number)
         if x >= 0.2:
             break
-    return x / number
+    return x / number / UNIQUE_KEYS
 
 
 prnt_form = (
@@ -43,13 +45,21 @@ def do(setup_statements, statement):
 )
 
 for curve in [i.name for i in curves]:
-    S1 = "import six; from ecdsa import SigningKey, %s" % curve
-    S2 = "sk = SigningKey.generate(%s)" % curve
-    S3 = "msg = six.b('msg')"
-    S4 = "sig = sk.sign(msg)"
-    S5 = "vk = sk.get_verifying_key()"
-    S6 = "vk.precompute()"
-    S7 = "vk.verify(sig, msg)"
+    S1 = "from ecdsa import SigningKey, %s" % curve
+    S1 += "; from ecdsa.util import PRNG"
+    # as the code is very much data dependant, use the same 100 keys
+    # to sign the same 100 messages over and over to make the
+    # benchmarking stable
+    S2 = (
+        "sk = ["
+        "SigningKey.generate({0}, entropy=PRNG(i)) "
+        "for i in range({1})]"
+    ).format(curve, UNIQUE_KEYS)
+    S3 = "msg = b'msg'"
+    S4 = "sig = [k.sign(msg, entropy=PRNG(b'A')) for k in sk]"
+    S5 = "vk = [k.get_verifying_key() for k in sk]"
+    S6 = "[k.precompute() for k in vk]"
+    S7 = "[k.verify(s, msg) for k, s in zip(vk, sig)]"
     # We happen to know that .generate() also calculates the
     # verifying key, which is the time-consuming part. If the code
     # were changed to lazily calculate vk, we'd need to change this
@@ -61,7 +71,7 @@ def do(setup_statements, statement):
     import ecdsa
 
     c = getattr(ecdsa, curve)
-    sig = ecdsa.SigningKey.generate(c).sign(six.b("msg"))
+    sig = ecdsa.SigningKey.generate(c).sign(b"msg")
     print(
         prnt_form.format(
             name=curve,
@@ -101,10 +111,25 @@ def do(setup_statements, statement):
     if curve == "Ed25519" or curve == "Ed448":
         continue
     S1 = "from ecdsa import SigningKey, ECDH, {0}".format(curve)
-    S2 = "our = SigningKey.generate({0})".format(curve)
-    S3 = "remote = SigningKey.generate({0}).verifying_key".format(curve)
-    S4 = "ecdh = ECDH(private_key=our, public_key=remote)"
-    S5 = "ecdh.generate_sharedsecret_bytes()"
+    S1 += "; from ecdsa.util import PRNG"
+    # as with signatures, calculate shared secrets for the same
+    # set of keys over and over
+    S2 = (
+        "our = ["
+        "SigningKey.generate({0}, entropy=PRNG(i)) "
+        "for i in range({1})]"
+    ).format(curve, UNIQUE_KEYS)
+    S3 = (
+        "remote = ["
+        "SigningKey.generate({0}, entropy=PRNG(i+10)).verifying_key "
+        "for i in range({1})]"
+    ).format(curve, UNIQUE_KEYS)
+    S4 = (
+        "ecdh = ["
+        "ECDH(private_key=o, public_key=r) "
+        "for o, r in zip(our, remote)]"
+    )
+    S5 = "[e.generate_sharedsecret_bytes() for e in ecdh]"
     ecdh = do([S1, S2, S3, S4], S5)
     print(
         ecdh_form.format(