using System;

using System.Text;

using System.IO;

using System.Security.Cryptography;

public class Program

{

    public static void Main()

    {

        string text = "$5$34$1$8$";     

        string en = AES128_Encrypt_ECB(text, "BMEIMPL@YYYYMMDD");       

        string de = AES128_Decrypt_ECB(en, "BMEIMPL@YYYYMMDD");  

        Console.WriteLine("Text : "+text);

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

        Console.WriteLine("Decrypted Text : "+de);

    }

    public static string AES128_Encrypt_ECB(string plainText, string strKey)

        {

            byte[] encrypted;

            byte[] Key = Encoding.UTF8.GetBytes(strKey);

            using (AesManaged aes = new AesManaged())

            {

                aes.Key = Key;

                aes.Padding = PaddingMode.PKCS7;

                aes.Mode = CipherMode.ECB;

                ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

                using (MemoryStream ms = new MemoryStream())

                {

                    using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))

                    { 

                        using (StreamWriter sw = new StreamWriter(cs))

                            sw.Write(plainText);

                        encrypted = ms.ToArray();

                    }

                }

            }

            return Convert.ToBase64String(encrypted);

        }

​

        public static string AES128_Decrypt_ECB(string strEncryptText, string strKey)

        {

            string plaintext = null;

            byte[] Key = Encoding.UTF8.GetBytes(strKey);

            byte[] cipherText = Convert.FromBase64String(strEncryptText);

            using (AesManaged aes = new AesManaged())

            {

                aes.Key = Key;

                aes.Padding = PaddingMode.PKCS7;

                aes.Mode = CipherMode.ECB;

                ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);  

                using (MemoryStream ms = new MemoryStream(cipherText))

                {

                    using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))

                    {

                        using (StreamReader reader = new StreamReader(cs))

                            plaintext = reader.ReadToEnd();

                    }

                }

            }

            return plaintext;

        }

​

}