Java - RSA + AES a double layer security system - Architecture + Implementation example

Hello everyone, today we will learn a double-layer security system using RSA+AES in Java, with the help of architecture visualization and one java example.

  • Encryption's primary purpose is to protect against brute force attacks. It is composed of a cipher, the message/data, and a key (the password). With a wide range of free tools available like(Aircrack-ng, John the Ripper, Rainbow Crack, and L0phtCrack ), even baby hackers can attempt to hack passwords using brute force.
  • In my opinion, as a layperson in cryptography, multiple double-layer encryptions may not increase security, but it may slow down attackers.
  • Using encryption may cause performance issues. Or maybe not. It really depends on how you use it. If you understand just how "expensive" each part of your enterprise encryption operation is, it's possible you can avoid the expensive parts and dramatically increase the performance of your applications.
Let's see the architecture of the RSA + AES system




This is the top layer architecture of a double-layer security system.

We will explain the RSA + AES security system with the help of one Java program, you can easily implement this algorithm on another programming platform.


SecurityUtil.java

package com.knf.sibin.dev;

import java.io.UnsupportedEncodingException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.util.Arrays;
import java.util.Base64;
import java.util.Base64.Encoder;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

/**
 * @author sibinmuhammed
 *
 */
public class SecurityUtil {
    private static SecretKeySpec secretKey;
    private static byte[] key;
    private static final String ASYMMETRIC_ALGORITHM = "RSA";

    // set Key
    public static void setKey(String myKey) {
        MessageDigest sha = null;
        try {
            key = myKey.getBytes("UTF-8");
            sha = MessageDigest.getInstance("SHA-1");
            key = sha.digest(key);
            key = Arrays.copyOf(key, 16);
            secretKey = new SecretKeySpec(key, "AES");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }

    // method to encrypt the secret text using key
    public static String encrypt(String strToEncrypt, String secret) {
        try {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
            return Base64.getEncoder().encodeToString(cipher.doFinal
              (strToEncrypt.getBytes("UTF-8")));
        } catch (Exception e) {
            System.out.println("Error while encrypting: " + e.toString());
        }
        return null;
    }

    // method to encrypt the secret text using key
    public static String decrypt(String strToDecrypt, String secret) {
        try {
            setKey(secret);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey);
            return new String(cipher.doFinal(Base64.getDecoder().
               decode(strToDecrypt)));
        } catch (Exception e) {
            System.out.println("Error while decrypting: " + e.toString());
        }
        return null;
    }

    // Get RSA keys. Uses key size of 2048.
    public static Map<String, Object> getRSAKeys() throws Exception {
        KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
        keyPairGenerator.initialize(2048);
        KeyPair keyPair = keyPairGenerator.generateKeyPair();
        PrivateKey privateKey = keyPair.getPrivate();
        PublicKey publicKey = keyPair.getPublic();

        Map<String, Object> keys = new HashMap<String, Object>();
        keys.put("private", privateKey);
        keys.put("public", publicKey);
        return keys;
    }

    // Decrypt using RSA public key
    public static String decryptMessage(String encryptedText, 
              PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        return new String(cipher.doFinal(Base64.getDecoder().
              decode(encryptedText)));
    }

    // Encrypt using RSA private key
    public static String encryptMessage(String plainText, 
          PrivateKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        return Base64.getEncoder().encodeToString(cipher.doFinal
          (plainText.getBytes()));
    }

    // Encrypt using RSA private key
    public static String encryptMessageUsingPublic(String plainText, 
              PublicKey privateKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, privateKey);
        return Base64.getEncoder().encodeToString(cipher.doFinal
                (plainText.getBytes()));
    }

    // Decrypt using RSA public key
    public static String decryptMessagePrivateKey(String encryptedText, 
           PrivateKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, publicKey);
        return new String(cipher.doFinal(Base64.getDecoder().
           decode(encryptedText)));
    }

    public static String secureRandomString() {
        SecureRandom random = new SecureRandom();
        byte bytes[] = new byte[20];
        random.nextBytes(bytes);
        Encoder encoder = Base64.getUrlEncoder().withoutPadding();
        String token = encoder.encodeToString(bytes);
        return token;
    }
}



Below is our demo driver class to test the double-layer security system.

Demo.java

package com.knf.sibin.dev;

import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.Map;

// Java 8 RSA+AES encryption/decryption
// Uses strong encryption with 2048 key size.
public class Demo {

    public static void main(String[] args) throws Exception {

        /*
         * Step 1
         * 
         * @Client: Generate Public and Private Key
         */
        Map<String, Object> keys = SecurityUtil.getRSAKeys();
        PrivateKey privateKey = (PrivateKey) keys.get("private");
        PublicKey publicKey = (PublicKey) keys.get("public");
        System.out.println("Key Pairs generated on client-side");

        /*
         * Step 2
         *
         * @Client: Sent public key to the server and save the private key on 
          client local storage
         * 
         */
        System.out.println("private-key store on client-side");
        System.out.println("sent public-key  to server-side");

        /*
         * Step 3
         * 
         * @Server: Server will generate a secure random aes_key
         */
        String secure_random_aes_key = SecurityUtil.secureRandomString();
        System.out.println("Generate Secure Random AES key on server-side");

        /*
         * Step 4
         * 
         * @Server:Ecrypt the AES key using public key and store the AES key on
         * server-side.
         */
        String encrptText = SecurityUtil.encryptMessageUsingPublic
           (secure_random_aes_key, publicKey);
        System.out.println("Encrypted the AES key using public key");
        System.out.println("AES key stored on server");

        /*
         * Step 5
         * 
         * @Server:Sent encrypted AES key to client-side
         */
        System.out.println("Sent encrypted AES key to client-side");

        /*
         * Step 6
         * 
         * @Client: Decrypt the encrypted AES key using private key
         */
        String aesKey = SecurityUtil.decryptMessagePrivateKey
            (encrptText, privateKey);
        System.out.println("AES key successfully decrypted");

        /*
         * Step 7
         * 
         * @Client:Encrypt the secrets using AES key and sent it to server-side
         */
        String enc = SecurityUtil.encrypt("password-Sibin777!88", aesKey);
        System.out.println("Secret succesfully encrypted");
        System.out.println("Encrypted secret successfully sent to server");

        /*
         * Step 8
         * 
         * @Server:Decrypt the secret using AES key
         */
        String secret = SecurityUtil.decrypt(enc, aesKey);
        System.out.println("Successfully decrypted, Your secret is:" + secret);

    }

}

If you execute this Java class, you will get the following output
Key Pairs generated on client-side
private-key store on client-side
sent public-key  to server-side
Generate Secure Random AES key on server-side
Encrypted the AES key using the public key
AES key stored on the server
Sent encrypted AES key to client-side
AES key successfully decrypted
Secret successfully encrypted
Encrypted secret successfully sent to the server
Successfully decrypted, Your secret is:password-Sibin777!88

Popular posts from this blog

Learn Java 8 streams with an example - print odd/even numbers from Array and List

Example 1: Java 8 program to print odd numbers from a List   import java.util.Arrays; import java.util.List; import java.util.stream.Collectors; /*Java 8 Program to find Odd Numbers from a List*/ public class DriverClass { public static void main( String [] args) { List < Integer > numbers = Arrays. asList( 1 , 4 , 8 , 40 , 11 , 22 , 33 , 99 ); List < Integer > oddNumbers = numbers.stream(). filter(o -> o % 2 != 0 ). collect(Collectors.toList()); System.out.println(oddNumbers); } } 1. Initialize List using Arrays.asList() method. Java's built-in Arrays.asList() method converts an array into a list. This method takes an array as an argument and returns a List object. 2.  Java List interface provides stream() method which returns a sequential Stream with list of Integer as its source. 3. The Java stream filter() method allow
Read more

Java Stream API - How to convert List of objects to another List of objects using Java streams?

Image
In this section, we will show you how to convert a List of objects to another List of objects in Java using the Java streams map(). The ‘map’ method maps each element to its corresponding result. Java Stream API   The Java Stream API provides a functional programming approach over the object oriented capabilities of Java. It is used for processing collections of objects. The Stream in Java can be defined as a sequence of elements from a source List, Set or Array. Most of the stream operations return a Stream. This avails engender a chain of stream operations(stream pipe-lining). The streams withal support the aggregate or terminal operations on the elements. for example, finding the sum or maximum element or finding the average etc...Stream operations can either be executed sequentially or parallel. when performed parallelly, it is called a parallel stream.   Stream map() Method   The Java 8 Stream map() is an intermediate operation. It converts Stream<obj1> to Stream<obj2>
Read more

Registration and Login with Spring Boot + Spring Security + Thymeleaf

Image
In this section, we will learn how to create user registration and login using Spring boot, Spring security, Thymeleaf, JPA, and H2DB. The GitHub repository link is provided at the end of this tutorial. You can download the source code. Technologies used: Spring Boot 2.5.5  Spring Data JPA  Spring Security  Thymeleaf  Maven 3+  Java 17  H2 Database   User Interface User Registration Authentication Failed Authentication success Sign out Final Project Structure: Complete pom.xml: <? xml version ="1.0" encoding ="UTF-8" ?> < project xmlns ="http://maven.apache.org/POM/4.0.0" xmlns: xsi ="http://www.w3.org/2001/XMLSchema-instance" xsi :schemaLocation ="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" > < modelVersion >4.0.0</ modelVersion > < parent > < groupId >org.springframework.boot</ groupId > < artifactId >spring-boot-starter-pare
Read more

Java, Spring Boot Mini Project - Library Management System - Download

Image
Hello everyone, Hope you are doing well. Here, we provide a Library Management System mini-project for beginners, it's free for download. Maybe you can build more on top of this project and create your own product, that's all about you. The source code download link is provided at the end of this post. 1. Benefit of this project You could cover the following technologies and features by learning and debugging this mini project. Java 17 Java Stream Java Lamda Expressions Java Records Functional programming Object-oriented programming var Keyword in Java Generics in Java Java Switch Spring boot 2.6.4 Spring Security Thymeleaf template engine OpenCSV Spring Data JPA Server Side Pagination H2 Database  Bootstrap HTML CSS and more... 2. Objective Of Spring Boot On Library Management System The main objective of this project is to manage the details of the books, author, category, and publisher. Only Admin/Librarian will manage all these activities. Also, they can export the data in
Read more

ReactJS, Spring Boot JWT Authentication Example

Image
In this tutorial, we’ll create a user registration & login example using ReactJS, Spring Boot, Spring Security, and JWT authentication. You could download the source code from our Github repository, the download link is provided at the end of this tutorial. Technologies used Backend Technologies: Java 17 Spring Boot 2.7.0 Spring Security Spring Data JPA JWT H2 Database Frontend Technologies: React 17.0.1 Axios 0.27.2 Redux 4.0.5 Bootstrap 4.5.2 ReactJS - SpringBoot - JWT - Flow Backend Project Directory: Frontend Project Directory: Following is the screenshot of our application - User Registration: User Signin: Profile View: Access Resource: We will build two projects:  1. Backend:   spring-boot-security-jwt 2. Frontend: react-redux-jwt Project 1: spring-boot-security-jwt Pom.xml <?xml version = "1.0" encoding = "UTF-8" ?> <project xmlns = "http://maven.apache.org/POM/4.0.0" xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
Read more

Top 5 Java ORM tools - 2024

Image
  The term ORM refers to object-relational mapping, which uses objects to adapt programming languages to database systems while allowing them to function with SQL and object-oriented programming ideas. Any kind of database management system that can accomplish object mapping to the table in the virtual system is suitable for the implementation of ORM. Java has a wide variety of ORM tools, some of which are mentioned below: 1. Hibernate Hibernate is a lightweight, open-source, non-invasive Java ORM (Object-Relational Mapping) framework that allows developers to create objects that function independently of database software and create persistence logic in any Java or JavaEE application. It offers an abstraction layer, so developers don't have to bother about implementations; Hibernate handles these tasks internally, such as connecting to databases and creating queries to carry out CRUD operations, among other things. Persistence logic development is done with it. Persistence logic r
Read more

Java - Blowfish Encryption and decryption Example

Image
Blowfish is an encryption method developed by Bruce Schneier in 1993 as an alternative to the DES encryption method. It is significantly faster than DES and provides good encryption speed, although no effective cryptanalysis technique has been found to date. It is one of the first secure block ciphers that is not protected by any patents and is therefore freely available for anyone to use. This is a symmetric block cipher algorithm. Block size: 64 bits Key size: variable size from 32 to 448 bits number of subsections: 18 [P-array] number of rounds: 16 number of substitution blocks: 4 [each with 512 records of 32 bits each] develop  Example 1: Encryption and decryption using Blowfish import java.io.UnsupportedEncodingException; import java.nio.charset.Charset; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; import java.util.Base64; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeExc
Read more

Spring boot video streaming example-HTML5

Image
Hello everyone, Today we will learn how to stream MP4 video using Spring Boot and Spring Web Flux.  The Source code download link is provided at the end of this post. New, Quarkus Practice User Interface   Project Structure: G radle(build.gradle) plugins { id 'org.springframework.boot' version '2.5.4' id 'io.spring.dependency-management' version '1.0.11.RELEASE' id 'java' } group = 'com.knf.demo' version = '0.0.1-SNAPSHOT' sourceCompatibility = '11' repositories { mavenCentral() } dependencies { implementation 'org.springframework.boot:spring-boot-starter-webflux' testImplementation 'org.springframework.boot:spring-boot-starter-test' testImplementation 'io.projectreactor:reactor-test' } test { useJUnitPlatform() } Service (VideoStreamingService.java) package  com.knf.demo.service ; import org.springframework.beans.factory.annotation. Autowired ; import org.springframework
Read more

Google Cloud Storage + Spring Boot - File Upload, Download, and Delete

Image
In this section, we will learn  how to  create a simple spring boot application to perform different file operations such as upload, download, list, and delete files from the Google Cloud Storage. 1.  A little bit of Background Google Cloud Storage Cloud Storage is a managed service for storing unstructured data. Store any amount of data and retrieve it as often as you like. More Info - click here! Spring Boot Spring Boot makes it easy to create stand-alone, production-grade Spring-based Applications that you can "just run".  More Info - click here! 2. Create a GCP Project First, Sign into the Google console at  https://console.cloud.google.com . You can create a new project by first selecting the project dropdown in the top left and selecting " New Project ". Next, specify your GCP  Project name  and  Project ID . Then  Click on the " CREATE " button. Copy " Project ID " and keep it for future purposes. 3. Create a Google Cloud Storage bucket Fr
Read more