ChronoCrypt: Time-Locked Secure Notes with Self-Destruct 🔐⏳

ChronoCrypt is a powerful CLI-based encryption tool that allows users to create time-locked secure notes that self-destruct after a specified duration. It uses AES-256 encryption (CBC mode) to securely store sensitive information, ensuring that notes are unreadable beyond their expiry time.

🔹 AES-256 Encryption for Maximum Security
🔹 Self-Destructing Notes After Expiry
🔹 User-Friendly Command-Line Interface
🔹 Supports Expiry Times in Minutes, Hours, or Days

🚀 Features

✅ AES-256 Encryption: Strong encryption using SHA-256 derived keys.
✅ Time-Locked Access: Notes can only be read before expiry.
✅ Automatic Secure Deletion: Notes are irreversibly deleted after expiry.
✅ User-Friendly CLI: Simple commands for encryption & decryption.
✅ Supports Expiry Formats: Set time in minutes (m), hours (h), or days (d).

🛠️ Tech Stack

Technology	Description
🐍 Python	Programming Language
🔐 PyCryptodome	AES-256 Encryption Library
📂 OS	File Handling & Secure Deletion

📌 Prerequisites

• Python 3.x (Download: Python.org)

⚡ Installation & Usage

1️⃣ Clone the Repository

git clone https://github.com/trinetra110/ChronoCrypt.git
cd ChronoCrypt  

2️⃣ Install Dependencies

pip install -r requirements.txt  

3️⃣ Encrypt a Secure Note

python main.py encrypt "Your Secret Message" "YourPassword" -t 30m -f my_secret.sec  

• Your Secret Message → The message to encrypt
• YourPassword → The password for encryption/decryption
• -t 30m → (Optional) The note will self-destruct in 30 minutes (supports m, h, d) (default: 1h).
• -f my_secret.sec → (Optional) Save the note to a custom file (binary like .sec) (default: sec_note.sec).

4️⃣ Decrypt & Read a Note (Before Expiry)

python main.py decrypt my_secret.sec "YourPassword"  

• If the note is not expired, the decrypted message will be displayed.
• If the note is expired, it will be securely deleted automatically.

🎯 How It Works

1️⃣ Encryption:

• The message is encrypted using AES-256 (CBC mode).
• A time-lock mechanism ensures notes are valid only until expiry.
• The encrypted note is saved in a .sec file.

2️⃣ Decryption & Expiry Check:

• When attempting to decrypt, the expiry timestamp is checked.
• If not expired, the message is decrypted and displayed.
• If expired, the note is securely deleted to prevent access.

3️⃣ Secure Deletion:

• The file is overwritten with random bytes before deletion.
• This prevents forensic recovery of the note.

🏆 Why Use ChronoCrypt?

🔹 Store Temporary Secrets: Ideal for one-time secure message sharing.
🔹 Automated Data Expiry: No need to manually delete expired notes.
🔹 Lightweight & Fast: CLI-based tool, no additional setup required.
🔹 Bulletproof Security: AES-256 encryption with automatic secure deletion.

📜 License

This project is licensed under the MIT License.