确保加密的字符串不包含/

Question

public static string Encryptor(string plainText, string EncryptionKey)
    {
        byte[] clearBytes = Encoding.Unicode.GetBytes(plainText);

        Aes encryptor = Aes.Create();
        Rfc2898DeriveBytes pdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
        encryptor.Key = pdb.GetBytes(32);
        encryptor.IV = pdb.GetBytes(16);

        MemoryStream ms = new MemoryStream();
        using (CryptoStream cs = new CryptoStream(ms, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
        {
            cs.Write(clearBytes, 0, clearBytes.Length);
            cs.Close();
        }
        plainText = Convert.ToBase64String(ms.ToArray());

        return plainText;
    }

这是我用来确保文件名安全的代码，但问题是有时诸如 / 之类的字符对于文件创建来说是不可接受的，如果我想打开它，则 System.IO.FileStream 将 / 后面的部分检测为显然不存在的文件夹。

我对 Aes 还很陌生，那么我该怎么做才能确保 / 不会出现在加密代码中呢？