diff --git a/README.rst b/README.rst
index a7b8dc0..614dcb5 100644
--- a/README.rst
+++ b/README.rst
@@ -37,12 +37,12 @@ To install the latest version::
 
 Optional C Extension
 ====================
-PyOTA has an optional C extension that improves the performance of its
+PyOTA has optional C extensions that improve the performance of its
 cryptography features significantly (speedups of **60x** are common!).
 
-To install this extension, use the following command::
+To install these extensions, use the following command::
 
-   pip install pyota[ccurl]
+   pip install pyota[speedups]
 
 
 Installing from Source
diff --git a/iota/crypto/kerl/__init__.py b/iota/crypto/kerl/__init__.py
index 094b795..9ff9c2c 100644
--- a/iota/crypto/kerl/__init__.py
+++ b/iota/crypto/kerl/__init__.py
@@ -2,4 +2,11 @@
 from __future__ import absolute_import, division, print_function, \
     unicode_literals
 
-from .pykerl import *
+
+try:
+  from ckerl import Kerl, trits_to_bytes, bytes_to_trits, trits_to_trytes, \
+    trytes_to_trits
+except ImportError:
+  from .pykerl import Kerl
+  from .conv import trits_to_bytes, bytes_to_trits, trits_to_trytes, \
+    trytes_to_trits
diff --git a/iota/crypto/kerl/conv.py b/iota/crypto/kerl/conv.py
index 5541fa1..18feb2d 100644
--- a/iota/crypto/kerl/conv.py
+++ b/iota/crypto/kerl/conv.py
@@ -57,13 +57,13 @@ def trits_to_trytes(trits):
     return ''.join(trytes)
 
 
-def convertToTrits(bytes_k):
+def bytes_to_trits(bytes_k):
     bigInt = convertBytesToBigInt(bytes_k)
     trits = convertBigintToBase(bigInt, 3, TRIT_HASH_LENGTH)
     return trits
 
 
-def convertToBytes(trits):
+def trits_to_bytes(trits):
     bigInt = convertBaseToBigint(trits, 3)
     bytes_k = convertBigintToBytes(bigInt)
     return bytes_k
diff --git a/iota/crypto/kerl/pykerl.py b/iota/crypto/kerl/pykerl.py
index 86edcb5..1a4c437 100644
--- a/iota/crypto/kerl/pykerl.py
+++ b/iota/crypto/kerl/pykerl.py
@@ -66,7 +66,7 @@ def absorb(self, trits, offset=0, length=None):
             if stop - offset == TRIT_HASH_LENGTH:
                 trits[stop - 1] = 0
 
-            signed_nums = conv.convertToBytes(trits[offset:stop])
+            signed_nums = conv.trits_to_bytes(trits[offset:stop])
 
             # Convert signed bytes into their equivalent unsigned
             # representation, in order to use Python's built-in bytes
@@ -127,7 +127,7 @@ def squeeze(self, trits, offset=0, length=None):
 
             signed_hash = [conv.convert_sign(b) for b in unsigned_hash]
 
-            trits_from_hash = conv.convertToTrits(signed_hash)
+            trits_from_hash = conv.bytes_to_trits(signed_hash)
             trits_from_hash[TRIT_HASH_LENGTH - 1] = 0
 
             stop = min(TRIT_HASH_LENGTH, length - offset)
diff --git a/setup.py b/setup.py
index 444dfc9..398f72b 100644
--- a/setup.py
+++ b/setup.py
@@ -76,6 +76,8 @@
 
   extras_require = {
     'ccurl': ['pyota-ccurl'],
+    'ckerl': ['ckerl'],
+    'speedups': ['pyota-ccurl', 'ckerl'],
     'docs-builder': ['sphinx', 'sphinx_rtd_theme'],
     'test-runner': ['detox'] + tests_require,
   },
diff --git a/test/crypto/kerl/pykerl_test.py b/test/crypto/kerl/pykerl_test.py
index 3e48169..72db0bb 100644
--- a/test/crypto/kerl/pykerl_test.py
+++ b/test/crypto/kerl/pykerl_test.py
@@ -10,7 +10,7 @@
 from sha3 import keccak_384
 
 from iota.crypto.kerl import Kerl
-from iota.crypto.kerl.conv import convertToBytes, convertToTrits, \
+from iota.crypto.kerl import trits_to_bytes, bytes_to_trits, \
   trits_to_trytes, trytes_to_trits
 
 
@@ -105,16 +105,16 @@ def test_input_greater_243(self):
     def test_all_bytes(self):
         for i in range(-128, 128):
             in_bytes = [i] * 48
-            trits = convertToTrits(in_bytes)
-            out_bytes = convertToBytes(trits)
+            trits = bytes_to_trits(in_bytes)
+            out_bytes = trits_to_bytes(trits)
 
             self.assertEqual(in_bytes, out_bytes)
 
     def test_random_trits(self):
         in_trits = [randrange(-1,2) for _ in range(243)]
         in_trits[242] = 0
-        in_bytes = convertToBytes(in_trits)
-        out_trits = convertToTrits(in_bytes)
+        in_bytes = trits_to_bytes(in_trits)
+        out_trits = bytes_to_trits(in_bytes)
 
         self.assertEqual(in_trits, out_trits)