Encryption And Decryption Using A Symmetric Key In C#

Symmetric key in C#

The symmetric key is a string used to encrypt the data, and with the exact string, we can decrypt the data, which means a single string is required for encryption and decryption

 

Encryption & Decryption code:

namespace YourNamespace
{
    using System;
    using System.IO;
    using System.Security.Cryptography;
    using System.Text;
    public class CryptoHelper
    {
        private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        public static string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey[..8]);
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new();
                MemoryStream mStream = new();
                CryptoStream cStream = new(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }
        public static string DecryptDES(string decryptString, string decryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey[..8]);
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Convert.FromBase64String(decryptString);
                DESCryptoServiceProvider DCSP = new();
                MemoryStream mStream = new();
                CryptoStream cStream = new(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
            catch (Exception ex)
            {
                return decryptString;
            }
        }
    }
}

Summary:

Learn how to use a symmetric key for encryption and decryption in C#. As per our requirement, we can also use different methods present inside the CryptoHelper Class