diff --git a/chapter_one/Multiplikative_Chiffre.py b/chapter_one/Multiplikative_Chiffre.py
index 5157422..1dc57b3 100644
--- a/chapter_one/Multiplikative_Chiffre.py
+++ b/chapter_one/Multiplikative_Chiffre.py
@@ -3,11 +3,11 @@ from utils import AlphabetUtils as au
 ALLOWED_KEYS = [1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, 25]
 
 
-def encrypt_text(key: int = 11, cleartext: str = 'BonkRocks'):
+def encrypt_text(cleartext: str, key: int):
 	"""
 	Encrypts the given text with the given key
-	:param key: The key to use. Has to be between 1 and 25 and a coprime to 26.
 	:param cleartext: The text to encrypt
+	:param key: The key to use. Has to be between 1 and 25 and a coprime to 26.
 	:return: The encrypted text
 	"""
 	# Key has to be coprime to 26
@@ -24,11 +24,11 @@ def encrypt_text(key: int = 11, cleartext: str = 'BonkRocks'):
 	return resulting
 
 
-def decrypt_text(key: int = 11, ciphertext: str = 'lyngfywgq'):
+def decrypt_text(ciphertext: str, key: int):
 	"""
 	Decrypts the given ciphertext with the given key
-	:param key: The key to use. Has to be between 1 and 25 and a coprime to 26.
 	:param ciphertext: The text to decrypt
+	:param key: The key to use. Has to be between 1 and 25 and a coprime to 26.
 	:return: The decrypted text
 	"""
 	# Key has to be coprime to 26
@@ -61,5 +61,5 @@ def _get_key_reverse(key: int):
 
 
 if __name__ == '__main__':
-	print(encrypt_text())
-	print(decrypt_text())
+	print(encrypt_text('BonkRocks', 11))
+	print(decrypt_text('lyngfywgq', 11))
diff --git a/chapter_one/Permutations-Chiffre.py b/chapter_one/Permutations-Chiffre.py
new file mode 100644
index 0000000..153a091
--- /dev/null
+++ b/chapter_one/Permutations-Chiffre.py
@@ -0,0 +1,55 @@
+import random
+
+from utils import AlphabetUtils as au
+
+
+def encrypt_text(cleartext: str, key: [int]):
+	"""
+	Encrypts the given text with the given key
+	:param cleartext: The text to encrypt
+	:param key: The key to use. Has to be a list of indices of the alphabet, so [0...25] shuffled
+	:return: The encrypted text
+	"""
+	resulting = ''
+
+	for char in cleartext:
+		charIndex = au.get_index_of_letter(char)
+		cipherIndex = key.index(charIndex)
+		cipherChar = au.get_letter_at_index(cipherIndex)
+		resulting += cipherChar
+
+	return resulting
+
+
+def decrypt_text(ciphertext: str, key: [int]):
+	"""
+	Decrypts the given ciphertext with the given key
+	:param ciphertext: The text to decrypt
+	:param key: The key to use. Has to be a list of indices of the alphabet, so [0...25] shuffled
+	:return: The decrypted text
+	"""
+	resulting = ''
+
+	for char in ciphertext:
+		charIndex = au.get_index_of_letter(char)
+		clearIndex = key[charIndex]
+		clearChar = au.get_letter_at_index(clearIndex)
+		resulting += clearChar
+
+	return resulting
+
+
+def _generate_key():
+	indices = [i for i in range(26)]
+
+	random.shuffle(indices)
+
+	return indices
+
+
+if __name__ == '__main__':
+	key = _generate_key()
+	print(key)
+	encrypted = encrypt_text('BonkRocks', key)
+	print(encrypted)
+	print(decrypt_text(encrypted, key))
diff --git a/chapter_one/Tausch-Chiffre.py b/chapter_one/Tausch-Chiffre.py
index 761d30c..03fd32f 100644
--- a/chapter_one/Tausch-Chiffre.py
+++ b/chapter_one/Tausch-Chiffre.py
@@ -3,12 +3,12 @@ from utils import AlphabetUtils as au
 ALLOWED_KEYS = [1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, 25]
 
 
-def encrypt_text(key1: int = 11, key2: int = 7, cleartext: str = 'BonkRocks'):
+def encrypt_text(cleartext: str, key1: int, key2: int):
 	"""
 	Encrypts the given text with the given keys
+	:param cleartext: The text to encrypt
 	:param key1: The first key. Has to be between 1 and 25 and a coprime to 26
 	:param key2: The second key. Has to be between 0 and 26
-	:param cleartext: The text to encrypt
 	:return: The encrypted text
 	"""
 	# key1 has to be coprime to 26
@@ -29,12 +29,12 @@ def encrypt_text(key1: int = 11, key2: int = 7, cleartext: str = 'BonkRocks'):
 	return resulting
 
 
-def decrypt_text(key1: int = 11, key2: int = 7, ciphertext: str = 'sfunmfdnx'):
+def decrypt_text(ciphertext: str, key1: int, key2: int):
 	"""
 	Decrypts the given ciphertext with the given keys
+	:param ciphertext: The text to decrypt
 	:param key1: The first key. Has to be between 1 and 25 and a coprime to 26
 	:param key2: The second key. Has to be between 0 and 26
-	:param ciphertext: The text to decrypt
 	:return: The decrypted text
 	"""
 	# key1 has to be coprime to 26
@@ -71,5 +71,5 @@ def _get_key_reverse(key: int):
 
 
 if __name__ == '__main__':
-	print(encrypt_text())
-	print(decrypt_text())
+	print(encrypt_text('BonkRocks', 11, 7))
+	print(decrypt_text('sfunmfdnx', 11, 7))