Encrypt

Command line application to encrypt and decrypt any file with a password.

Usage

# Using bash
./encrypt -f <file> -k <key> -e
./encrypt -f <file> -k <key> -d

# Using python
python3 encrypt -f <file> -k <key> -e
python3 encrypt -f <file> -k <key> -d

Arguments

-f --file to encrypt, required
-k --key key to use for encryption, required
-e --encrypt encrypt the file, optional
-d --decrypt decrypt the file, optional
-s --sneaky do not append .enc to filename

Notes

Considerations

• encrypt or decrypt must be specified
• you must have python and pip installed
• the cryptography package will be installed automatically if not found

Security

Brute Force Attack Estimates

This application uses PBKDF2 with 100,000 iterations, making each password guess take approximately 0.1 seconds on a modern CPU.

Password Type	Entropy	Time to Crack
8 random lowercase	~38 bits	Minutes to hours
8 random alphanumeric	~48 bits	Years
12 random alphanumeric	~71 bits	Millions of years
16 random alphanumeric	~95 bits	Billions of years
"password123"	Dictionary attack	Seconds

Recommendations

• Minimum: 12+ random characters (letters, numbers, symbols)
• Alternative: 4-5 word passphrase (e.g., "correct-horse-battery-staple")
• Avoid: Dictionary words, personal info, patterns, or common passwords

Technical Details

• Algorithm: Fernet (AES-128-CBC + HMAC-SHA256)
• Key Derivation: PBKDF2-HMAC-SHA256 with 100,000 iterations
• Salt: 32 random bytes generated per file using secrets.token_bytes()
• Salt Storage: Prepended to encrypted file (first 32 bytes)