DNK-2 🔐🧬

A modern encryption algorithm with DNA steganography.

DNK-2 is a cryptographic system that encrypts data using ChaCha20 and then encodes the ciphertext into a DNA-like sequence (A, C, G, T). The result looks like a real DNA strand — perfect for steganography, biological data storage, or just for fun.

"I didn't know it was impossible, so I did it."

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✨ Features

• ✅ ChaCha20 stream cipher (256-bit key)
• ✅ PBKDF2 key derivation (600,000 iterations)
• ✅ HMAC-SHA256 authentication (integrity check)
• ✅ DNA encoding — 00→A, 01→C, 10→G, 11→T
• ✅ Marker structure — [DNA-nonce][AAAA][DNA-data][TTTT]
• ✅ Text and file encryption
• ✅ GUI (Tkinter) — user-friendly interface
• ✅ UTF-8 support (Russian, emoji, etc.)
• ✅ Steganography-ready — output indistinguishable from real DNA

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📦 Installation

git clone https://github.com/yourusername/DNK-2.git
cd DNK-2
pip install -r requirements.txt
python dnk2.py

Dependencies:

• Python 3.8+
• cryptography library

🚀 How to use

Encrypt: - Run the program - Choose Text or File - Enter your message or select a file - Set a password - Click Encrypt - Save the .DNK file Decrypt: - Open the program - Go to Decrypt - Select your .DNK file - Enter the same password - Click Decrypt - Get your original data back

# ⚠️ Note: The "key" shown after encryption is just the nonce — it's already inside the file. You only need the password to decrypt.

🧬 File format

[16 bytes salt] [DNA-nonce (64 chars)] [AAAA] [DNA-encrypted data] [TTTT]

- .DNK files are plain text (A/C/G/T) + binary salt at the beginning
- The nonce is encoded in DNA and stored at the start of the sequence
- Markers AAAA and TTTT ensure correct parsing

🔐 Security

• Feature Value
• Key size 256 bits
• Nonce size 128 bits (16 bytes)
• KDF PBKDF2-HMAC-SHA256, 600k iterations
• Cipher ChaCha20
• Authentication HMAC-SHA256
• Brute-force resistance 2²⁵⁶ operations (physically impossible)

📁 Project structuretext

• DNK-2/
• ├── dnk2.py # Encrypter/Decryptor
• ├── SPECIFICATION.md # Full algorithm specification (ENG)
• ├── RUS_SPECIFICATION.txt # Full algorithm specification (RUS)
• ├── README.md # This file
• └── requirements.txt # Dependencies

🧪 Example

Input: "Hi" Password: "test" Output: text

TЎЃ4аJЦl��ЌЈ~dgўCTGCGAGCGATAATTCCTTATCCGATGTGTAGCTTCGCGAAGCCAATGTAGAGCAGTGTGGTGCAAAAAGGGTAACCGAGAGTTACATTTT...

👨‍💻 Author

• Alexey Kazakevich Country: Russia

📜 License

GNU GPL v3 — use it, learn from it, improve it. ⭐ Support

If you like this project, give it a star on GitHub! Pull requests, issues, and ideas are always welcome.