How to Encrypt and Decrypt Strings in Python?
Last Updated :
14 Aug, 2024
In this article, we will learn about Encryption, Decryption and implement them with Python.
Encryption:
Encryption is the process of encoding the data. i.e converting plain text into ciphertext. This conversion is done with a key called an encryption key.
Decryption:
Decryption is the process of decoding the encoded data. Converting the ciphertext into plain text. This process requires a key that we used for encryption.
We require a key for encryption. There are two main types of keys used for encryption and decryption. They are Symmetric-key and Asymmetric-key.
Symmetric-key Encryption:
In symmetric-key encryption, the data is encoded and decoded with the same key. This is the easiest way of encryption, but also less secure. The receiver needs the key for decryption, so a safe way need for transferring keys. Anyone with the key can read the data in the middle.
Example:
Install the python cryptography library with the following command.
pip install cryptography
Steps:
- Import Fernet
- Then generate an encryption key, that can be used for encryption and decryption.
- Convert the string to a byte string, so that it can be encrypted.
- Instance the Fernet class with the encryption key.
- Then encrypt the string with the Fernet instance.
- Then it can be decrypted with Fernet class instance and it should be instanced with the same key used for encryption.
Python
from cryptography.fernet import Fernet
# we will be encrypting the below string.
message = "hello geeks"
# generate a key for encryption and decryption
# You can use fernet to generate
# the key or use random key generator
# here I'm using fernet to generate key
key = Fernet.generate_key()
# Instance the Fernet class with the key
fernet = Fernet(key)
# then use the Fernet class instance
# to encrypt the string string must
# be encoded to byte string before encryption
encMessage = fernet.encrypt(message.encode())
print("original string: ", message)
print("encrypted string: ", encMessage)
# decrypt the encrypted string with the
# Fernet instance of the key,
# that was used for encrypting the string
# encoded byte string is returned by decrypt method,
# so decode it to string with decode methods
decMessage = fernet.decrypt(encMessage).decode()
print("decrypted string: ", decMessage)
Output:

Asymmetric-key Encryption:
In Asymmetric-key Encryption, we use two keys a public key and a private key. The public key is used to encrypt the data and the private key is used to decrypt the data. By the name, the public key can be public (can be sent to anyone who needs to send data). No one has your private key, so no one in the middle can read your data.
Example:
Install the python rsa library with the following command.
pip install rsa
Steps:
- Import rsa library
- Generate public and private keys with rsa.newkeys() method.
- Encode the string to byte string.
- Then encrypt the byte string with the public key.
- Then the encrypted string can be decrypted with the private key.
- The public key can only be used for encryption and the private can only be used for decryption.
Python
import rsa
# generate public and private keys with
# rsa.newkeys method,this method accepts
# key length as its parameter
# key length should be atleast 16
publicKey, privateKey = rsa.newkeys(512)
# this is the string that we will be encrypting
message = "hello geeks"
# rsa.encrypt method is used to encrypt
# string with public key string should be
# encode to byte string before encryption
# with encode method
encMessage = rsa.encrypt(message.encode(),
publicKey)
print("original string: ", message)
print("encrypted string: ", encMessage)
# the encrypted message can be decrypted
# with ras.decrypt method and private key
# decrypt method returns encoded byte string,
# use decode method to convert it to string
# public key cannot be used for decryption
decMessage = rsa.decrypt(encMessage, privateKey).decode()
print("decrypted string: ", decMessage)
Output:

Similar Reads
Python Tutorial - Learn Python Programming Language Python is one of the most popular programming languages. Itâs simple to use, packed with features and supported by a wide range of libraries and frameworks. Its clean syntax makes it beginner-friendly. It'sA high-level language, used in web development, data science, automation, AI and more.Known fo
10 min read
Python Interview Questions and Answers Python is the most used language in top companies such as Intel, IBM, NASA, Pixar, Netflix, Facebook, JP Morgan Chase, Spotify and many more because of its simplicity and powerful libraries. To crack their Online Assessment and Interview Rounds as a Python developer, we need to master important Pyth
15+ min read
Non-linear Components In electrical circuits, Non-linear Components are electronic devices that need an external power source to operate actively. Non-Linear Components are those that are changed with respect to the voltage and current. Elements that do not follow ohm's law are called Non-linear Components. Non-linear Co
11 min read
Python OOPs Concepts Object Oriented Programming is a fundamental concept in Python, empowering developers to build modular, maintainable, and scalable applications. By understanding the core OOP principles (classes, objects, inheritance, encapsulation, polymorphism, and abstraction), programmers can leverage the full p
11 min read
Python Projects - Beginner to Advanced Python is one of the most popular programming languages due to its simplicity, versatility, and supportive community. Whether youâre a beginner eager to learn the basics or an experienced programmer looking to challenge your skills, there are countless Python projects to help you grow.Hereâs a list
10 min read
Python Exercise with Practice Questions and Solutions Python Exercise for Beginner: Practice makes perfect in everything, and this is especially true when learning Python. If you're a beginner, regularly practicing Python exercises will build your confidence and sharpen your skills. To help you improve, try these Python exercises with solutions to test
9 min read
Python Programs Practice with Python program examples is always a good choice to scale up your logical understanding and programming skills and this article will provide you with the best sets of Python code examples.The below Python section contains a wide collection of Python programming examples. These Python co
11 min read
Spring Boot Tutorial Spring Boot is a Java framework that makes it easier to create and run Java applications. It simplifies the configuration and setup process, allowing developers to focus more on writing code for their applications. This Spring Boot Tutorial is a comprehensive guide that covers both basic and advance
10 min read
Python Introduction Python was created by Guido van Rossum in 1991 and further developed by the Python Software Foundation. It was designed with focus on code readability and its syntax allows us to express concepts in fewer lines of code.Key Features of PythonPythonâs simple and readable syntax makes it beginner-frien
3 min read
Python Data Types Python Data types are the classification or categorization of data items. It represents the kind of value that tells what operations can be performed on a particular data. Since everything is an object in Python programming, Python data types are classes and variables are instances (objects) of thes
9 min read