diff --git a/api/app.py b/api/app.py
index e24647a..937db44 100644
--- a/api/app.py
+++ b/api/app.py
@@ -1,28 +1,28 @@
 import traceback
 
-from flask_openapi3 import Info
-from flask_openapi3 import OpenAPI, APIBlueprint
+from cipher_algorithms.ciphers.polygram_substitution_cipher.algo import (
+    UnsupportedCharacterError,
+)
+from cipher_algorithms.helpers.char_conversion_27 import InvalidCharacterException
 from flask import redirect
+from flask_openapi3 import APIBlueprint, Info, OpenAPI
 
+from .ciphers.base64 import base64_blueprint
 from .ciphers.bifid import bifid_blueprint
 from .ciphers.caesar import caesar_blueprint
 from .ciphers.columnar_transposition import columnar_transposition_blueprint
 from .ciphers.fractioned_morse import fractioned_morse_blueprint
+from .ciphers.hill import hill_blueprint
 from .ciphers.homophonic_substitution import homophonic_substitution_blueprint
 from .ciphers.mono_alphabetic_substitution import mono_alphabetic_substitution_blueprint
 from .ciphers.one_time_pad import one_time_pad_blueprint
+from .ciphers.playfair import playfair_blueprint
 from .ciphers.polyalphabetic_substitution import polyalphabetic_substitution_blueprint
 from .ciphers.polybius import polybius_blueprint
 from .ciphers.polygram_substitution import polygram_substitution_cipher_blueprint
 from .ciphers.rail_fence import rail_fence_cipher_blueprint
 from .ciphers.vigenere import vigenere_blueprint
-
 from .common.schemas import ExceptionSchema
-from cipher_algorithms.helpers.char_conversion_27 import InvalidCharacterException
-from cipher_algorithms.ciphers.polygram_substitution_cipher.algo import (
-    UnsupportedCharacterError,
-)
-
 
 info = Info(title="Cipher Algorithm API", version="0.0.1")
 app = OpenAPI(__name__, info=info, doc_prefix="/docs", swagger_url="/")
@@ -68,13 +68,16 @@ def homepage():
     return redirect("docs")
 
 
+ciphers.register_api(base64_blueprint)
 ciphers.register_api(bifid_blueprint)
 ciphers.register_api(caesar_blueprint)
 ciphers.register_api(columnar_transposition_blueprint)
 ciphers.register_api(fractioned_morse_blueprint)
+ciphers.register_api(hill_blueprint)
 ciphers.register_api(homophonic_substitution_blueprint)
 ciphers.register_api(mono_alphabetic_substitution_blueprint)
 ciphers.register_api(one_time_pad_blueprint)
+ciphers.register_api(playfair_blueprint)
 ciphers.register_api(polyalphabetic_substitution_blueprint)
 ciphers.register_api(polybius_blueprint)
 ciphers.register_api(polygram_substitution_cipher_blueprint)
diff --git a/tests/base64/test_base64.py b/tests/base64/test_base64.py
new file mode 100644
index 0000000..7d54d10
--- /dev/null
+++ b/tests/base64/test_base64.py
@@ -0,0 +1,18 @@
+from cipher_algorithms.ciphers.base64.algo import (
+    encrypt,
+    decrypt,
+)
+
+
+def test_base64_encrypt():
+    plaintext = "testingabc"
+    cipher = encrypt(plaintext)
+
+    assert cipher == "dGVzdGluZ2FiYw=="
+
+
+def test_base64_decrypt():
+    cipher = "dGVzdGluZ2FiYw=="
+    plaintext = decrypt(cipher)
+
+    assert plaintext == "testingabc"
diff --git a/tests/hill/test_hill.py b/tests/hill/test_hill.py
new file mode 100644
index 0000000..248d984
--- /dev/null
+++ b/tests/hill/test_hill.py
@@ -0,0 +1,20 @@
+from cipher_algorithms.ciphers.hill.algo import (
+    encrypt,
+    decrypt,
+)
+
+
+def test_hill_encrypt():
+    plaintext = "TESTINGABC"
+    key = "HELLO"
+    cipher = encrypt(plaintext, key)
+
+    assert cipher == "VQXVRTQYDA"
+
+
+def test_hill_decrypt():
+    plaintext = "VQXVRTQYDA"
+    key = "HELLO"
+    cipher = decrypt(plaintext, key)
+
+    assert cipher == "TESTINGABC"
diff --git a/tests/playfair/test_playfair.py b/tests/playfair/test_playfair.py
new file mode 100644
index 0000000..70974f4
--- /dev/null
+++ b/tests/playfair/test_playfair.py
@@ -0,0 +1,20 @@
+from cipher_algorithms.ciphers.playfair.algo import (
+    encrypt,
+    decrypt,
+)
+
+
+def test_playfair_encrypt():
+    plaintext = "TESTINGABC"
+    key = "HELLO"
+    cipher = encrypt(plaintext, key)
+
+    assert cipher == "ROTUKPPGCD"
+
+
+def test_playfair_decrypt():
+    plaintext = "ROTUKPPGCD"
+    key = "HELLO"
+    cipher = decrypt(plaintext, key)
+
+    assert cipher == "TESTINGABC"