Companies made these decisions about encryption when they were finding it very difficult to sell their products overseas because the [Edward] Snowden disclosures created the impression that the U.S. government was inside this hardware and software produced by them. They needed to do something to deal with the perception.

The thing we've learned from the last 20 years of counterterrorism is the significant value you get from removing leadership from the battlefield in degrading the organization.

I'm concerned, too, about ISIS' ability, right, to infiltrate people. But we have got some very effective, robust processes for vetting people. We brought in thousands of Iraqi refugees after the Iraq War. Not a single one has ever turned out to be a terrorist because the vetting was so good.

[Hillary Clinton] never misused [ information that the Central Intelligence Agency has]. She always protected it. I would trust her with the crown jewels of the United States government. And, more importantly, I would trust her with the future security of the country and the future security of my kids.

The [Edward] Snowden disclosures created this perception that people's privacy was being put at significant risk.

As the briefer, my job is to carry CIA`s best information and best analysis to the president of the United States and make sure he understands it.

As far as Paris goes, we don't know for sure yet how these guys communicate among themselves and how they communicated back to the ISIS leadership in Iraq and Syria, but I'm fairly confident we're going to learn they used these encrypted communication applications that have commercial encryption and are extremely difficult for companies to break - and which the companies have made the decision not to produce a key for.