using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

​

public class AesEncryption

{

    private static string encryptionKey = "PZYvdF18G3OowTKueNwLkjc3iPCQnQuv"; // Replace with your actual encryption key

​

    public static string EncryptAES(string plaintext)

    {

        byte[] byteMsg = Encoding.UTF8.GetBytes(plaintext);

​

        using (Aes aesAlg = Aes.Create())

        {

            aesAlg.Key = Encoding.UTF8.GetBytes(encryptionKey);

            aesAlg.Mode = CipherMode.CFB;

​

            byte[] iv = new byte[aesAlg.BlockSize / 8];

            using (var rng = new RNGCryptoServiceProvider())

            {

                rng.GetBytes(iv);

            }

​

            using (ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, iv))

            using (MemoryStream msEncrypt = new MemoryStream())

            {

                msEncrypt.Write(iv, 0, iv.Length);

                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))

                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))

                {

                    swEncrypt.Write(plaintext);

                }

​

                return Convert.ToBase64String(msEncrypt.ToArray());

            }

        }

    }

    public static void Main()

    {

        string plaintext = "Hello, world!";

        string encryptedText = EncryptAES(plaintext);

        Console.WriteLine("Encrypted Text: " + encryptedText);

    }

}

​

​