Insider only
From what I have read on this appointment, Giuliani's role is unofficial and undefined. The Prez-elect is one of those characters who needs to pad his inner circle with those he knows really well and trusts to a fault. His family and close friends are like his force field.
The Twumpster has shown a distrust and disdain for all US intelligent agency intel and has a penchant for conspiracy theories. I think Giuliani's responsibilities will be totally void of plugging security holes - he will probably focus on how the administration should react to countries and individuals that unleash cyber attacks on the US. There are government departments that will address industrial espionage and infrastructure vulnerability while Giuliani will probably be a mere filter for the Prez. on what the spy agencies conclude and recommend. Can't see him expert in any other advisory capacity.