encrypt-descrypt c#

		#region Encrypt/Decrypt
		public static class EncryptDecrypt
		{
			// encryption
			public static string EncryptString(string messageToEncrypt, string key_ )
			{
				CryptoStream cryptoStream; MemoryStream memoryStream;
				helper__encrypt_decrypt_stream(out memoryStream, out cryptoStream, secterKey);
				string encryptedText = String.Empty;
				try
				{
					byte[] plainBytes = Encoding.ASCII.GetBytes(plainText); 	// Convert the plainText string into a byte array

					cryptoStream.Write(plainBytes, 0, plainBytes.Length);  		// Encrypt the input plaintext string

					cryptoStream.FlushFinalBlock();                         	// Complete the encryption process

					byte[] cipherBytes = memoryStream.ToArray();            	// Convert the encrypted data from a MemoryStream to a byte array




					encryptedText = Convert.ToBase64String(cipherBytes, 0, cipherBytes.Length);  // Convert the encrypted byte array to a base64 encoded string
				}
				catch (Exception e)
				{
					return e.Message;
				}
				finally
				{
					memoryStream.Close();
					cryptoStream.Close();
				}
				return encryptedText;
			}


			public static string DecryptString(string encryptedText, string secterKey)
			{














				CryptoStream cryptoStream; MemoryStream memoryStream;
				helper__encrypt_decrypt_stream(out memoryStream, out cryptoStream, secterKey);





				string plainText = String.Empty;
				try
					byte[] cipherBytes = Convert.FromBase64String(encryptedText);// Convert the encryptedText string into a byte array
					cryptoStream.Write(cipherBytes, 0, cipherBytes.Length);		// Decrypt the input encryptedText string
					cryptoStream.FlushFinalBlock();              				// Complete the decryption process
					byte[] plainBytes = memoryStream.ToArray();					// Convert the decrypted data from a MemoryStream to a byte array

					plainText = Encoding.ASCII.GetString(plainBytes, 0, plainBytes.Length); // Convert the decrypted byte array to string
				}
				catch (Exception e)
				{
					return e.Message;











				}
				finally
				{

					memoryStream.Close();
					cryptoStream.Close();
				}

				return plainText;
			}

			public static void helper__encrypt_decrypt_stream(out MemoryStream memoryStream, out CryptoStream cryptoStream, string secterKey)
			{
				SHA256 mySHA256 = SHA256Managed.Create();
				byte[] key = mySHA256.ComputeHash(Encoding.ASCII.GetBytes(secterKey));
				byte[] iv = new byte[16] { 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0 };
				// string symmetric encryption
				Aes encryptor = Aes.Create();
				encryptor.Mode = CipherMode.CBC;
				//encryptor.KeySize = 256;    encryptor.BlockSize = 128;   encryptor.Padding = PaddingMode.Zeros;
				encryptor.Key = key;
				encryptor.IV = iv;

				memoryStream = new MemoryStream();
				cryptoStream = new CryptoStream(memoryStream, encryptor.CreateEncryptor(), CryptoStreamMode.Write); // write to memory stream
			}
		}