This is a symmetric encryption/decryption tool that uses a dictionary-based cipher algorithm. It allows you to encrypt and decrypt text using a secret key.

The encryption algorithm works by:
1. Taking each character from your text
2. Finding its position in the selected dictionary
3. Taking the corresponding character from the key
4. Adding their positions together (modulo dictionary length)
5. Using the resulting character as the encrypted output

Decryption reverses this process by subtracting positions instead of adding.

ENCRYPTION:
1. Enter your plain text in the top textarea
2. Enter a secret key in the key field
3. Select a dictionary (see below)
4. Optionally check 'morph' for stronger encryption
5. Click 'Encript top' button
6. The encrypted text appears in the bottom textarea

DECRYPTION:
1. Enter encrypted text in the bottom textarea
2. Enter the same secret key used for encryption
3. Select the same dictionary used for encryption
4. Check 'morph' if it was used during encryption
5. Click 'Decript bottom' button
6. The decrypted text appears in the top textarea

- int: Full international dictionary (all printable ASCII + Russian Cyrillic)
- eng: English dictionary (ASCII printable characters only)
- rus: Russian dictionary (Cyrillic characters only)
- simple_int: Simplified international (alphanumeric + Cyrillic)
- simple_eng: Simplified English (alphanumeric only)
- simple_rus: Simplified Russian (numbers + Cyrillic only)

IMPORTANT: The key must only contain characters from the selected dictionary!

When enabled, the encryption key automatically changes during encryption based on the encrypted output. This makes the encryption stronger but:
- Slows down encryption/decryption of large texts
- Must be enabled for both encryption AND decryption
- The key evolves as encryption progresses

- Encrypted text cannot contain raw tab characters, newlines, backslashes, or quotes
- These characters are automatically escaped (\t, \n, \\, \")
- Characters not in the selected dictionary are preserved as-is

This is a simple educational tool. For real security, use modern encryption algorithms like AES. This tool is suitable for obfuscation and learning purposes only.