Rsa encryption in c#

gistfile1.txt

 public static string Encrypt(string plainText, string publicKey)
        {
            UnicodeEncoding _encoder = new UnicodeEncoding();

            var rsa = new RSACryptoServiceProvider();
            rsa.FromXmlString(publicKey);
            var dataToEncrypt = _encoder.GetBytes(plainText);
            var encryptedByteArray = rsa.Encrypt(dataToEncrypt, false).ToArray();
           return Convert.ToBase64String(encryptedByteArray);
        }