public TripleDESCrypt()
{
tdes = new TripleDESCryptoServiceProvider();
tdes.Mode = CipherMode.CBC;
tdes.Key = Encoding.UTF8.GetBytes(this.Rot13(Constants.Key)); //半角24文字 196bit
tdes.IV = Encoding.UTF8.GetBytes(hash.ComputeMD5(Constants.IV).Substring(0, 8)); //半角8文字 64bit
}