Cybercrime and cyberterrorism are both growing at rates between 20% and 40%, said Giuliani, who made a brief return from the Republican National Convention in Cleveland to speak at BlackBerry's New York event.
"Think of it like cancer. We can't cure it... but if we catch it early we can put it into remission," he said. The quicker you can spot an attack, the less chance there is of loss.
Furthermore, systems designers are not starting with security in mind, Giuliani said.
"This is going to be the challenge of our next 10 to 15 years."
Giuliani suggested that state-sponsored attacks aren't the problem, because the MAD (mutually assured destruction) doctrine applies just as it did in the old war. If China tried to put the lights out in the US, the US could do the same to China.
And nations with "insane" leaders are largely kept in check by their military and technical people
Terrorist groups are a different issue, because MAD does not apply and it takes time to track them down.
"We didn't pay him a dime" to speak at the summit, said BlackBerry executive chairman and chief executive John Chen. "He believes in what we do."
Disclosure: The writer attended the BlackBerry Security Summit as a guest of the company