Implementing RSA Encryption and Decryption in Python

by

What will you learn?

In this tutorial, you will delve into the intriguing realm of cryptography by learning how to implement RSA encryption and decryption in Python. By the end of this guide, you will have a comprehensive understanding of how to apply one of the most robust encryption techniques available today to secure your data effectively.

Introduction to the Problem and Solution

Cryptography plays a vital role in ensuring secure communication between frontend applications and backend APIs, safeguarding sensitive information from unauthorized access. The RSA algorithm, named after Rivest-Shamir-Adleman who introduced it in 1978, is a widely utilized form of public-key cryptography that enables secure data exchange even over insecure channels. The objective here is to create an RSA encryption-decryption system using Python. This approach guarantees that intercepted data remains incomprehensible to unauthorized parties without access to the private key.

To achieve this goal, we will begin by generating a pair of keys: a public key for encryption and a private key for decryption. Subsequently, these keys will be used for encrypting sensitive information before transmission from the frontend (client-side) and decrypting it at the backend (server-side). Through a combination of practical code implementation and theoretical insights into RSA’s inner workings, we aim not only to provide coding solutions but also deepen your understanding of cryptographic principles.

Code

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_OAEP
import binascii

# Generating a private key (RsaKey object) with a key length of 1024 bits
private_key = RSA.generate(1024)
public_key = private_key.publickey()

def rsa_encrypt(public_key, message):
    cipher = PKCS1_OAEP.new(public_key)
    encrypted_message = cipher.encrypt(message.encode('utf-8'))
    return binascii.hexlify(encrypted_message).decode('utf-8')

def rsa_decrypt(private_key, encrypted_message):
    encrypted_msg_bytes = binascii.unhexlify(encrypted_message)
    cipher = PKCS1_OAEP.new(private_key)
    decrypted_message = cipher.decrypt(encrypted_msg_bytes)
    return decrypted_message.decode('utf-8')

# Example usage:
message_to_encrypt = "Hello World"
encrypted_msg = rsa_encrypt(public_key,message_to_encrypt )
print("Encrypted:", encrypted_msg)

decrypted_msg=rsa_decrypt(private_key , encrypted_msg )
print("Decrypted:", decrypted_msg)

# Copyright PHD

Explanation

The provided code illustrates how to generate an RSA key pair (consisting of a public and private key), encrypt a message using the public key, and subsequently decrypt it using the corresponding private key in Python utilizing the pycryptodome library.

Steps Explained: 1. Generate Keys: Generate an RSA private_key with RSA.generate() specifying 1024 bits as our desired size. 2. Public Key Derivation: Derive public_key from the generated private_key. 3. Encryption Function (rsa_encrypt): Create an ‘cipher’ instance using PKCS1_OAEP.new() with the public key for optimal asymmetric encryption padding. 4. Decryption Function (rsa_decrypt): Convert hex string back into bytes before decrypting via OAEP using the original private key. 5. Demonstrated are example calls showcasing encryption from plain text (‘Hello World’) to its encrypted form followed by successful decryption back to the initial input.

This process ensures data confidentiality during transmission since interceptors require access to specific secret components (private part) exclusively known among authorized entities involved within communication pipelines.

  1. How does asymmetric cryptography work?

  2. Asymmetric cryptography employs two mathematically linked keys � one public for encrypting messages shared openly without compromising security; another privately held used strictly among communicating parties responsible solely upon decoding incoming texts/data ensuring authenticity & confidentiality simultaneously.

  3. Is 1024-bit encryption safe?

  4. While 1024-bit keys were once deemed secure, advancements in computing power recommend higher standards like 2048-bits or beyond based on evolving cyber threats requiring updated security measures across digital platforms/services globally.

  5. Can I use larger keys than 2048-bits?

  6. Yes! Increasing bit-size enhances strength exponentially albeit impacting computational costs potentially affecting performance particularly on lower-end hardware configurations necessitating optimization strategies for seamless user experience amidst cryptographic operations background complexities within architectures.

  7. …and more questions answered comprehensively throughout FAQ section.

Conclusion

Mastering techniques such as implementing algorithms like RSA in Python equips individuals and organizations with modern cryptography tools to enhance communication security amid digitalization where privacy concerns escalate daily interactions across various sectors. By empowering users with control over their digital identities through robust security measures, we contribute towards creating safer digital environments fostering trust and reliability across interconnected networks globally.

Leave a Comment