Python에서 비밀번호를 사용하여 문자열을 안전하게 암호화하고 해독하는 방법은 무엇입니까?

<code class="python">from cryptography.fernet import Fernet, FernetException

password = 'mypass'  
fernet = Fernet(password.encode())

encrypted_message = fernet.encrypt(b'John Doe')
decrypted_message = fernet.decrypt(encrypted_message)

print(encrypted_message)  # Encrypted string
print(decrypted_message.decode())  # 'John Doe'</code>

<code class="python">import secrets

from cryptography.fernet import Fernet
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC

backend = default_backend()
salt = secrets.token_bytes(16)  # Generate a unique salt
password = 'mypass'.encode()  # Convert password to bytes

kdf = PBKDF2HMAC(
    algorithm=hashes.SHA256(), length=32, salt=salt, iterations=100000,
    backend=backend
)
key = b64e(kdf.derive(password))  # Derive the secret key

fernet = Fernet(key)
encrypted_message = fernet.encrypt(b'John Doe')</code>