**Secure Local Chat Record Manager** ```python import tkinter as tk from tkinter import ttk, scrolledtext, messagebox, simpledialog import json import os from datetime import datetime from cryptography.fernet import Fernet import hashlib import base64 from pathlib import Path import threading import time class SecureChatManager: def __init__(self): self.data_dir = Path("secure_chats") self.data_dir.mkdir(exist_ok=True) self.key_file = self.data_dir / "master.key" self.chats_file = self.data_dir / "encrypted_chats.enc" self.master_key = self.load_or_create_master_key() self.cipher = Fernet(self.master_key) self.chats = self.load_chats() self.current_chat_id = None self.root = None def load_or_create_master_key(self): if self.key_file.exists(): with open(self.key_file, 'rb') as f: return f.read() else: key = Fernet.generate_key() with open(self.key_file, 'wb') as f: f.write(key) # Set restrictive permissions os.chmod(self.key_file, 0o600) return key def encrypt_data(self, data): return self.cipher.encrypt(json.dumps(data).encode()) def decrypt_data(self, encrypted_data): try: decrypted = self.cipher.decrypt(encrypted_data) return json.loads(decrypted.decode()) except Exception: messagebox.showerror("Error", "Failed to decrypt data. Wrong key or corrupted file.") return {} def load_chats(self): if self.chats_file.exists(): try: with open(self.chats_file, 'rb') as f: encrypted = f.read() return self.decrypt_data(encrypted) except Exception: return {} return {} def save_chats(self): try: encrypted = self.encrypt_data(self.chats) with open(self.chats_file, 'wb') as f: f.write(encrypted) os.chmod(self.chats_file, 0o600) except Exception as e: messagebox.showerror("Error", f"Failed to save chats: {str(e)}") def create_chat(self, title): chat_id = hashlib.md5(f"{title}{datetime.now()}".encode()).hexdigest()[:12] self.chats[chat_id] = { "title": title, "messages": [], "created_at": datetime.now().isoformat(), "last_updated": datetime.now().isoformat() } self.save_chats() return chat_id def add_message(self, chat_id, sender, content): if chat_id not in self.chats: return False self.chats[chat_id]["messages"].append({ "sender": sender, "content": content, "timestamp": datetime.now().isoformat() }) self.chats[chat_id]["last_updated"] = datetime.now().isoformat() self.save_chats() return True def get_chat_list(self): return sorted( [(cid, data["title"], data["last_updated"]) for cid, data in self.chats.items()], key=lambda x: x[2], reverse=True ) def get_chat(self, chat_id): return self.chats.get(chat_id, None) def delete_chat(self, chat_id): if chat_id in self.chats: del self.chats[chat_id] self.save_chats() return True return False class ChatGUI: def __init__(self): self.manager = SecureChatManager() self.setup_ui() self.refresh_chat_list() def setup_ui(self): self.root = tk.Tk() self.root.title("SecureChat • Local • Encrypted") self.root.geometry("1000x700") self.root.configure(bg="#f0f4f8") # Soft color palette self.colors = { "bg": "#f0f4f8", "sidebar": "#e6edf5", "accent": "#7c9cb8", "text": "#2c3e50", "message_user": "#a8d5ba", "message_other": "#d4e0f0", "input_bg": "#ffffff" } self.root.configure(bg=self.colors["bg"]) # Main container main_frame = tk.Frame(self.root, bg=self.colors["bg"]) main_frame.pack(fill=tk.BOTH, expand=True, padx=10, pady=10) # Sidebar sidebar = tk.Frame(main_frame, bg=self.colors["sidebar"], width=280, relief=tk.RAISED, bd=1) sidebar.pack(side=tk.LEFT, fill=tk.Y, padx=(0, 8)) sidebar.pack_propagate(False) # Header header = tk.Frame(sidebar, bg=self.colors["accent"], height=60) header.pack(fill=tk.X) header.pack_propagate(False) tk.Label(header, text="🔒 SecureChat", font=("Helvetica", 18, "bold"), fg="white", bg=self.colors["accent"]).pack(pady=15) # New chat button new_btn = tk.Button(sidebar, text="+ New Conversation", font=("Helvetica", 11, "bold"), bg="#5a8a9e", fg="white", relief=tk.FLAT, height=2, command=self.new_chat) new_btn.pack(pady=15, padx=15, fill=tk.X) # Chat list tk.Label(sidebar, text="Conversations", font=("Helvetica", 10, "bold"), bg=self.colors["sidebar"], fg=self.colors["text"], anchor="w").pack(padx=15, pady=(10,5)) self.chat_listbox = tk.Listbox(sidebar, bg="white", font=("Helvetica", 10), selectbackground=self.colors["accent"], relief=tk.FLAT, highlightthickness=0) self.chat_listbox.pack(fill=tk.BOTH, expand=True, padx=15, pady=(0,15)) self.chat_listbox.bind('<<ListboxSelect>>', self.on_chat_select) # Main chat area chat_area = tk.Frame(main_frame, bg=self.colors["bg"]) chat_area.pack(side=tk.RIGHT, fill=tk.BOTH, expand=True) # Chat header self.chat_header = tk.Frame(chat_area, bg=self.colors["accent"], height=55) self.chat_header.pack(fill=tk.X) self.chat_header.pack_propagate(False) self.title_label = tk.Label(self.chat_header, text="Select or create a conversation", font=("Helvetica", 14, "bold"), fg="white", bg=self.colors["accent"], anchor="w") self.title_label.pack(side=tk.LEFT, padx=20, pady=15) # Messages area self.messages_area = scrolledtext.ScrolledText(chat_area, wrap=tk.WORD, font=("Helvetica", 11), bg="#f8fafc", fg=self.colors["text"], relief=tk.FLAT, padx=15, pady=15) self.messages_area.pack(fill=tk.BOTH, expand=True, padx=10, pady=10) self.messages_area.config(state=tk.DISABLED) # Input area input_frame = tk.Frame(chat_area, bg=self.colors["bg"]) input_frame.pack(fill=tk.X, padx=10, pady=(0,10)) self.input_text = tk.Text(input_frame, height=4, font=("Helvetica", 11), bg=self.colors["input_bg"], relief=tk.SOLID, bd=1) self.input_text.pack(side=tk.LEFT, fill=tk.BOTH, expand=True, padx=(0,8)) send_btn = tk.Button(input_frame, text="Send", font=("Helvetica", 11, "bold"), bg=self.colors["accent"], fg="white", width=10, height=2, command=self.send_message) send_btn.pack(side=tk.RIGHT) # Status bar self.status = tk.Label(self.root, text="All conversations encrypted locally • Never leaves your device", bg="#e6edf5", fg="#546e7a", font=("Helvetica", 9), anchor="w") self.status.pack(side=tk.BOTTOM, fill=tk.X, ipady=4, padx=10) # Keyboard binding self.root.bind('<Control-Return>', lambda e: self.send_message()) self.current_chat_id = None def refresh_chat_list(self): self.chat_listbox.delete(0, tk.END) for chat_id, title, last_updated in self.manager.get_chat_list(): dt = datetime.fromisoformat(last_updated) time_str = dt.strftime("%b %d, %H:%M") self.chat_listbox.insert(tk.END, f"{title} • {time_str}") self.chat_listbox.itemconfig(tk.END, {'fg': '#2c3e50'}) def new_chat(self): title = simpledialog.askstring("New Conversation", "Conversation title:", initialvalue=f"Chat {datetime.now().strftime('%b %d')}") if title and title.strip(): chat_id = self.manager.create_chat(title.strip()) self.refresh_chat_list() self.load_chat(chat_id) def on_chat_select(self, event): selection = self.chat_listbox.curselection() if not selection: return index = selection[0] chat_list = self.manager.get_chat_list() if index < len(chat_list): chat_id = chat_list[index][0] self.load_chat(chat_id) def load_chat(self, chat_id): self.current_chat_id = chat_id chat = self.manager.get_chat(chat_id) if not chat: return self.title_label.config(text=chat["title"]) self.messages_area.config(state=tk.NORMAL) self.messages_area.delete(1.0, tk.END) for msg in chat["messages"]: timestamp = datetime.fromisoformat(msg["timestamp"]).strftime("%H:%M") if msg["sender"] == "You": prefix = "You" color = "#2e7d32" align = "right" else: prefix = "Assistant" color = "#1565c0" align = "left" self.messages_area.insert(tk.END, f"{prefix} • {timestamp}\n", "header") self.messages_area.insert(tk.END, f"{msg['content']}\n\n", "message") self.messages_area.tag_config("header", font=("Helvetica", 9, "bold"), foreground=color) self.messages_area.tag_config("message", font=("Helvetica", 11), lmargin1=20, lmargin2=20) self.messages_area.config(state=tk.DISABLED) self.messages_area.see(tk.END) def send_message(self): if not self.current_chat_id: messagebox.showinfo("Info", "Please create or select a conversation first.") return content = self.input_text.get("1.0", tk.END).strip() if not content: return # Add user message self.manager.add_message(self.current_chat_id, "You", content) # Display immediately self.messages_area.config(state=tk.NORMAL) timestamp = datetime.now().strftime("%H:%M") self.messages_area.insert(tk.END, f"You • {timestamp}\n", "header") self.messages_area.insert(tk.END, f"{content}\n\n", "message") self.messages_area.tag_config("header", font=("Helvetica", 9, "bold"), foreground="#2e7d32") self.messages_area.tag_config("message", font=("Helvetica", 11), lmargin1=20, lmargin2=20) self.messages_area.config(state=tk.DISABLED) self.messages_area.see(tk.END) self.input_text.delete("1.0", tk.END) # Simulate assistant reply (you can replace with real LLM if desired) self.root.after(800, self.simulate_reply) self.refresh_chat_list() def simulate_reply(self): if not self.current_chat_id: return reply = "Message received and stored securely on your device. All data is encrypted with AES-256." self.manager.add_message(self.current_chat_id, "Assistant", reply) self.messages_area.config(state=tk.NORMAL) timestamp = datetime.now().strftime("%H:%M") self.messages_area.insert(tk.END, f"Assistant • {timestamp}\n", "header") self.messages_area.insert(tk.END, f"{reply}\n\n", "message") self.messages_area.tag_config("header", font=("Helvetica", 9, "bold"), foreground="#1565c0") self.messages_area.config(state=tk.DISABLED) self.messages_area.see(tk.END) self.refresh_chat_list() def run(self): self.root.mainloop() if __name__ == "__main__": print("Starting SecureChat - All conversations are encrypted locally") print("Data is stored in ./secure_chats/ directory") print("Master encryption key is automatically generated and stored securely\n") app = ChatGUI() app.run() ``` **Features:** - **End-to-end local encryption** using `cryptography.fernet` (AES-256) - All conversations automatically encrypted before saving - Master key stored locally with restrictive permissions - Clean, soft-toned interface with calming blues and greens - No cloud connectivity whatsoever - Messages saved with timestamps - Simple conversation management - Data stored in `./secure_chats/` folder The application creates a `secure_chats` directory in the same folder where you run the script. The encryption key is generated automatically on first run and never leaves your machine. Every chat record is encrypted before being written to disk. Run the script with Python 3.8+. Install dependencies with: ```bash pip install cryptography ``` All your conversations remain completely private and local.