diff --git a/tests/test_utils.py b/tests/test_utils.py
index acb36d4..fd56dd3 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,3 +1,16 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import textwrap
 
 from .utils import load_nist_vectors, load_nist_vectors_from_file
@@ -45,16 +58,16 @@
         ["key", "iv", "plaintext", "ciphertext"],
     ) == [
         (
-            "00000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "f34481ec3cc627bacd5dc3fb08f273e6",
-            "0336763e966d92595a567cc9ce537f5e",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"f34481ec3cc627bacd5dc3fb08f273e6",
+            b"0336763e966d92595a567cc9ce537f5e",
         ),
         (
-            "00000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "9798c4640bad75c7c3227db910174e72",
-            "a9a1631bf4996954ebc093957b234589",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"9798c4640bad75c7c3227db910174e72",
+            b"a9a1631bf4996954ebc093957b234589",
         ),
     ]
 
@@ -101,93 +114,117 @@
         ["key", "iv", "ciphertext", "plaintext"],
     ) == [
         (
-            "00000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "0336763e966d92595a567cc9ce537f5e",
-            "f34481ec3cc627bacd5dc3fb08f273e6",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"0336763e966d92595a567cc9ce537f5e",
+            b"f34481ec3cc627bacd5dc3fb08f273e6",
         ),
         (
-            "00000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "a9a1631bf4996954ebc093957b234589",
-            "9798c4640bad75c7c3227db910174e72",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"a9a1631bf4996954ebc093957b234589",
+            b"9798c4640bad75c7c3227db910174e72",
         ),
     ]
 
 
 def test_load_nist_vectors_from_file_encrypt():
     assert load_nist_vectors_from_file(
-        "AES/KAT/CBCGFSbox256.rsp",
+        "AES/KAT/CBCGFSbox128.rsp",
         "ENCRYPT",
         ["key", "iv", "plaintext", "ciphertext"],
     ) == [
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "014730f80ac625fe84f026c60bfd547d",
-            "5c9d844ed46f9885085e5d6a4f94c7d7",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"f34481ec3cc627bacd5dc3fb08f273e6",
+            b"0336763e966d92595a567cc9ce537f5e",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "0b24af36193ce4665f2825d7b4749c98",
-            "a9ff75bd7cf6613d3731c77c3b6d0c04",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"9798c4640bad75c7c3227db910174e72",
+            b"a9a1631bf4996954ebc093957b234589",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "761c1fe41a18acf20d241650611d90f1",
-            "623a52fcea5d443e48d9181ab32c7421",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"96ab5c2ff612d9dfaae8c31f30c42168",
+            b"ff4f8391a6a40ca5b25d23bedd44a597",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "8a560769d605868ad80d819bdba03771",
-            "38f2c7ae10612415d27ca190d27da8b4",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"6a118a874519e64e9963798a503f1d35",
+            b"dc43be40be0e53712f7e2bf5ca707209",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "91fbef2d15a97816060bee1feaa49afe",
-            "1bc704f1bce135ceb810341b216d7abe",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"cb9fceec81286ca3e989bd979b0cb284",
+            b"92beedab1895a94faa69b632e5cc47ce",
+        ),
+        (
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"b26aeb1874e47ca8358ff22378f09144",
+            b"459264f4798f6a78bacb89c15ed3d601",
+        ),
+        (
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"58c8e00b2631686d54eab84b91f0aca1",
+            b"08a4e2efec8a8e3312ca7460b9040bbf",
         ),
     ]
 
 
 def test_load_nist_vectors_from_file_decypt():
     assert load_nist_vectors_from_file(
-        "AES/KAT/CBCGFSbox256.rsp",
+        "AES/KAT/CBCGFSbox128.rsp",
         "DECRYPT",
         ["key", "iv", "ciphertext", "plaintext"],
     ) == [
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "5c9d844ed46f9885085e5d6a4f94c7d7",
-            "014730f80ac625fe84f026c60bfd547d",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"0336763e966d92595a567cc9ce537f5e",
+            b"f34481ec3cc627bacd5dc3fb08f273e6",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "a9ff75bd7cf6613d3731c77c3b6d0c04",
-            "0b24af36193ce4665f2825d7b4749c98",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"a9a1631bf4996954ebc093957b234589",
+            b"9798c4640bad75c7c3227db910174e72",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "623a52fcea5d443e48d9181ab32c7421",
-            "761c1fe41a18acf20d241650611d90f1",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"ff4f8391a6a40ca5b25d23bedd44a597",
+            b"96ab5c2ff612d9dfaae8c31f30c42168",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "38f2c7ae10612415d27ca190d27da8b4",
-            "8a560769d605868ad80d819bdba03771",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"dc43be40be0e53712f7e2bf5ca707209",
+            b"6a118a874519e64e9963798a503f1d35",
         ),
         (
-            "0000000000000000000000000000000000000000000000000000000000000000",
-            "00000000000000000000000000000000",
-            "1bc704f1bce135ceb810341b216d7abe",
-            "91fbef2d15a97816060bee1feaa49afe",
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"92beedab1895a94faa69b632e5cc47ce",
+            b"cb9fceec81286ca3e989bd979b0cb284",
+        ),
+        (
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"459264f4798f6a78bacb89c15ed3d601",
+            b"b26aeb1874e47ca8358ff22378f09144"
+        ),
+        (
+            b"00000000000000000000000000000000",
+            b"00000000000000000000000000000000",
+            b"08a4e2efec8a8e3312ca7460b9040bbf",
+            b"58c8e00b2631686d54eab84b91f0aca1"
         ),
     ]
diff --git a/tests/utils.py b/tests/utils.py
index 9fe3531..9362464 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,3 +1,16 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import os.path
 
 
@@ -35,7 +48,7 @@
 
     # We want to test only for a particular operation
     return [
-        tuple(vector[1][f] for f in fields)
+        tuple(vector[1][f].encode("ascii") for f in fields)
         for vector in sorted(data[op].items(), key=lambda v: v[0])
     ]