Installation and Configuration
Programming Methodology
Video Tutorials

Basic Text Encryption and Decryption in C#

In this exercise, we will create a class called "Encrypter" that provides basic text encryption and decryption functionality. The class will include two static methods: Encrypt and Decrypt.

The Encrypt method will take a string as input and return an encrypted string by adding 1 to the ASCII value of each character. Similarly, the Decrypt method will reverse the encryption by subtracting 1 from each character's ASCII value.

Since these methods are static, we can use them directly without creating an instance of the Encrypter class. This simple encryption technique will help understand basic character manipulation and string transformations in C#.



Group

Advanced Classes in C#

Objective

1. Create a class named Encrypter.
2. Implement a static method Encrypt that shifts each character forward by one position in the ASCII table.
3. Implement a static method Decrypt that shifts each character backward by one position in the ASCII table.
4. In the Main method, demonstrate the encryption and decryption process using a sample text.
5. Display the original, encrypted, and decrypted texts.

Create a class "Encrypter" to encrypt and decrypt text.

It will have a "Encrypt" method, which will receive a string and return another string. It will be a static method, so that we do not need to create any object of type "Encrypter".

There will be also a "Decrypt" method.

In this first approach, the encryption method will be a very simple one: to encrypt we will add 1 to each character, so that "Hello" would become "Ifmmp", and to decrypt we would subtract 1 to each character.

An example of use might be: 

string newText = Encrypter.Encrypt("Hola");

Example C# Exercise

 Copy C# Code 
using System;

// Class to perform basic encryption and decryption
class Encrypter
{
    // Static method to encrypt a string by shifting each character forward by 1
    public static string Encrypt(string text)
    {
        char[] encryptedText = new char[text.Length];

        // Loop through each character and shift it forward in ASCII
        for (int i = 0; i < text.Length; i++)
        {
            encryptedText[i] = (char)(text[i] + 1);
        }

        // Return the encrypted text as a new string
        return new string(encryptedText);
    }

    // Static method to decrypt a string by shifting each character backward by 1
    public static string Decrypt(string text)
    {
        char[] decryptedText = new char[text.Length];

        // Loop through each character and shift it backward in ASCII
        for (int i = 0; i < text.Length; i++)
        {
            decryptedText[i] = (char)(text[i] - 1);
        }

        // Return the decrypted text as a new string
        return new string(decryptedText);
    }
}

// Main program
class Program
{
    static void Main()
    {
        // Original text to be encrypted
        string originalText = "Hello";

        // Encrypt the text
        string encryptedText = Encrypter.Encrypt(originalText);

        // Decrypt the text
        string decryptedText = Encrypter.Decrypt(encryptedText);

        // Display the results
        Console.WriteLine("Original text: " + originalText);
        Console.WriteLine("Encrypted text: " + encryptedText);
        Console.WriteLine("Decrypted text: " + decryptedText);
    }
}

 Output

Original text: Hello
Encrypted text: Ifmmp
Decrypted text: Hello

Share this C# Exercise

More C# Practice Exercises of Advanced Classes in C#

Explore our set of C# Practice Exercises! Specifically designed for beginners, these exercises will help you develop a solid understanding of the basics of C#. From variables and data types to control structures and simple functions, each exercise is crafted to challenge you incrementally as you build confidence in coding in C#.