Some months after [Keith Alexander] made that statement [Edward Snowden cause grave and irrevocable harm to the nation], the new director of the NSA, Michael Rogers, said that, in fact, he doesn't see the sky falling. It's not so serious after all.

When we look at the full-on mass surveillance watching everyone in the country, in the United States, it doesn't work. It didn't stop the attacks in Boston. The marathon bombings. Where again, we knew who these individuals were. It didn't stop the Underwear Bomber, whose father walked into an embassy and warned us about this individual before he walked onto an airplane. And it's not going to stop the next attacks either. Because again, they're not public safety programmes. They're spying programmes. They are valuable for spying.

When we talk about the assertion of basically new government privileges with weak or no justification, we don't even have to look at international law to see the failings in them.

Candidates run for election on campaign promises, but once they're elected they renege on those promises, which happened with President [Barack] Obama on Guantánamo, the surveillance programs and investigating the crimes of the Bush administration. These were very serious campaign promises that were not fulfilled.

Let's put it this way. The United States government has assembled a massive investigation team into me personally, into my work with the journalists, and they still have no idea what documents were provided to the journalist, what they have, what they don't have, because encryption works.

I have no relationship with the Russian government at all.

Anyway, it's not true that the authorities cannot access the content of the phone even if there is no back door. When I was at the NSA, we did this every single day, even on Sundays. I believe that encryption is a civic responsibility, a civic duty.