diff --git a/Tesla.py b/Tesla.py
index 7dedeef..7e856a0 100644
--- a/Tesla.py
+++ b/Tesla.py
@@ -1,5 +1,5 @@
 # Parameters and Arguments example
-def checkDriverAge(age=0):
+def check_driver_age(age=0):
     if int(age) < 18:
         print("Sorry, you are too young to drive this car. Powering off 😟")
     elif int(age) > 18:
@@ -8,4 +8,4 @@ def checkDriverAge(age=0):
         print("Congratulations on your first year of driving. Enjoy the ride! 🚀")
 
 
-checkDriverAge()
+check_driver_age()
diff --git a/find_duplicates.py b/find_duplicates.py
index b441a87..e36c8f6 100644
--- a/find_duplicates.py
+++ b/find_duplicates.py
@@ -1,10 +1,7 @@
 # Shows the duplicate strings
 my_list = ['a', 'b', 'c', 'd', 'd', 'm', 'm', 'n', 'o', 'z', 'z']
-
 duplicates = []
 for value in my_list:
-    if my_list.count(value) > 1:
-        if value not in duplicates:
-            duplicates.append(value)
-
+    if my_list.count(value) > 1 and value not in duplicates:
+        duplicates.append(value)
 print(duplicates)
diff --git a/performance_decorator.py b/performance_decorator.py
index d97d5c4..1f654de 100644
--- a/performance_decorator.py
+++ b/performance_decorator.py
@@ -1,21 +1,20 @@
-# Performance decorator
 from time import time
 
-
+# Decorator to measure performance
 def performance(fn):
     def wrapper(*args, **kwargs):
         t1 = time()
         result = fn(*args, **kwargs)
         t2 = time()
-        print(f'took {t2-t1} seconds')
+        print(f'took {t2 - t1} seconds')
         return result
     return wrapper
 
-
 @performance
 def long_time():
-    for i in range(10000000):
-        i*5
-
+    """Benchmarking function to test performance."""
+    for _ in range(10_000_000):
+        pass  # Empty loop for benchmarking the decorator
 
+# Execute the benchmark
 long_time()
diff --git a/strong_passgen_for_prod.py b/strong_passgen_for_prod.py
index a70e405..435c338 100644
--- a/strong_passgen_for_prod.py
+++ b/strong_passgen_for_prod.py
@@ -1,8 +1,8 @@
-# import modules
 import string
 import random
+import secrets
 
-# store all characters in lists
+# Store all characters in lists
 s1 = list(string.ascii_lowercase)
 s2 = list(string.ascii_uppercase)
 s3 = list(string.digits)
@@ -11,43 +11,50 @@
 # Ask user about the number of characters
 user_input = input("How many characters do you want in your password? ")
 
-# check this input is it number? is it more than 8?
+# Check if the input is a valid number and greater than or equal to 8
 while True:
     try:
         characters_number = int(user_input)
         if characters_number < 8:
-            print("Your password must be at least 8 characters long")
-            user_input = input("Please, Enter your number again: ")
+            print("Your password must be at least 8 characters long.")
+            user_input = input("Please, enter your number again: ")
         else:
             break
-    except:
-        print("Please, Enter a number")
-        user_input = input("Please, Enter your number again: ")
+    except ValueError:  # Catch invalid inputs
+        print("Invalid input. Please enter a valid number.")
+        user_input = input("Please, enter your number again: ")
 
-# shuffle all lists
-random.shuffle(s1)
-random.shuffle(s2)
-random.shuffle(s3)
-random.shuffle(s4)
+# Securely shuffle all character lists
+s1 = secrets.SystemRandom().sample(s1, len(s1))
+s2 = secrets.SystemRandom().sample(s2, len(s2))
+s3 = secrets.SystemRandom().sample(s3, len(s3))
+s4 = secrets.SystemRandom().sample(s4, len(s4))
 
-# calculate 30% & 20% of number of characters
-part1 = round(characters_number * (30 / 100))
-part2 = round(characters_number * (20 / 100))
+# Calculate portions of the password
+part1 = round(characters_number * 0.3)  # 30% lowercase and uppercase letters
+part2 = round(characters_number * 0.2)  # 20% digits and punctuations
 
-# generation of the password (60% letters and 40% digits & punctuations)
+# Generate the password
 result = []
-
 for x in range(part1):
     result.append(s1[x])
     result.append(s2[x])
-
 for x in range(part2):
     result.append(s3[x])
     result.append(s4[x])
 
-# shuffle the result
-random.shuffle(result)
+# Ensure the result has the exact number of characters requested
+while len(result) < characters_number:
+    result.append(secrets.choice(s1 + s2 + s3 + s4))
+
+# Securely shuffle the result using a cryptographically secure PRNG.
+secrets.SystemRandom().shuffle(result)   # Using SystemRandom ensures secure shuffling
 
-# join the result
+# Join the result to form the password
 password = "".join(result)
-print("Strong Password: ", password)
+
+# Mask the password except for the last 4 characters
+masked_password = '*' * (len(password) - 4) + password[-4:]
+
+# Output the masked password
+print("Generated password:", masked_password)