Added caesar hacker

RedLordezh7Venom · RedLordezh7Venom · commit 77951b800361 · 2024-10-24T21:53:32.000+05:30
diff --git a/Cipher_Encoder_Decoder/Cipher_Hacker/README.md b/Cipher_Encoder_Decoder/Cipher_Hacker/README.md
@@ -0,0 +1,47 @@
+# Caesar Cipher Hacker
+
+This Python script is designed to decode messages encrypted with the Caesar cipher by analyzing the text and determining the best shift value for decryption. It utilizes the Natural Language Toolkit (nltk) to evaluate the decoded messages based on recognized English words.
+
+## Features
+
+- Decodes Caesar cipher messages with varying shift values.
+- Automatically identifies the best shift for readability, thus cracking the shift value
+- Can work with text input or read from a specified file.
+
+## Requirements
+
+Before running the script, you need to set up the environment:
+
+1. **Install Dependencies**: Ensure you have the required Python packages by running:
+   ```bash
+   pip install nltk
+   ```
+2. **Download NLTK Resources**: Run `download_nltk_resources.py` to download necessary NLTK data files. 
+
+## Usage
+
+1. Ensure you've completed the setup steps above.
+2. You can either:
+   - Edit the `encoded_file.txt` to include your encoded message, or specify the file to be used (it can be a large text file).
+   - Or, input the encoded text directly when prompted.
+
+3. Run the script with:
+   ```bash
+   python cipherhacker.py
+   ```
+
+4. Follow the prompts:
+   - Enter `file` to read from `encoded_file.txt`(default) or any other file.
+   - Enter `text` to input the encoded message directly.
+
+## Output
+
+The script will display:
+- The shift value used for encoding.
+- The decoded message for the provided ciphertext.
+
+## Example
+
+To decode a message:
+1. Place your encoded text in `encoded_file.txt` or input any other txt file or have a sample ready to input.
+2. Run the script and follow the prompts.
diff --git a/Cipher_Encoder_Decoder/Cipher_Hacker/cipherhacker.py b/Cipher_Encoder_Decoder/Cipher_Hacker/cipherhacker.py
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+import nltk
+from nltk.corpus import words
+from nltk import word_tokenize
+from nltk import pos_tag
+
+# Load the set of English words
+english_words = set(words.words())
+
+def decode_caesar(ciphertext, shift):
+    decoded = []
+    for char in ciphertext:
+        if char.isalpha():
+            shift_base = ord('a') if char.islower() else ord('A')
+            decoded_char = chr((ord(char) - shift_base - shift) % 26 + shift_base)
+            decoded.append(decoded_char)
+        else:
+            decoded.append(char)  # Non-alpha characters remain unchanged
+    return ''.join(decoded)
+
+def evaluate_shift(decoded_message):
+    tokens = word_tokenize(decoded_message)
+    # Count recognized English words
+    score = sum(1 for word in tokens if word.lower() in english_words)
+    return score
+
+def find_best_shift(ciphertext):
+    best_shift = 0
+    highest_score = 0
+
+    for shift in range(1, 26):
+        decoded_message = decode_caesar(ciphertext, shift)
+        score = evaluate_shift(decoded_message)
+
+        if score > highest_score:
+            highest_score = score
+            best_shift = shift
+
+    return best_shift
+
+if __name__ == "__main__":
+    while True:
+        mode = input("Enter the type of input (file/text): ").strip().lower()
+
+        if mode == "file":
+            filename = input("Enter the name of the file (or press Enter to use 'encoded_file.txt'): ")
+            if not filename: 
+                filename = 'encoded_file.txt'
+            
+            try:
+                with open(filename, 'r') as file:
+                    encoded_text = file.read()
+                break  
+            except FileNotFoundError:
+                print(f"Error: The file '{filename}' was not found. Please try again.")
+                
+        elif mode == "text":
+            encoded_text = input("Enter the text: ")
+            break   
+            
+        else:
+            print("Invalid mode selected. Please enter 'file' or 'text'.")
+
+
+
+        
+    best_shift = find_best_shift(encoded_text)
+    print(f'The shift used was: {best_shift}')
+    print(f'Decoded message: {decode_caesar(encoded_text,best_shift)}')
diff --git a/Cipher_Encoder_Decoder/Cipher_Hacker/download_nltk_resources.py b/Cipher_Encoder_Decoder/Cipher_Hacker/download_nltk_resources.py
@@ -0,0 +1,9 @@
+import nltk
+
+# Download the necessary NLTK resources
+nltk.download('punkt')
+nltk.download('averaged_perceptron_tagger')
+nltk.download('words')
+nltk.download('punkt_tab')
+
+print("NLTK resources downloaded successfully.")
diff --git a/Cipher_Encoder_Decoder/Cipher_Hacker/encoded_file.txt b/Cipher_Encoder_Decoder/Cipher_Hacker/encoded_file.txt
@@ -0,0 +1 @@
+Wh ghm ptbm mh lmkbdx mbee max bkhg bl ahm, unm ftdx bm ahm ur lmkbdbgz.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+Wh ghm ptbm mh lmkbdx mbee max bkhg bl ahm, unm ftdx bm ahm ur lmkbdbgz.`