Q: How do you feel about the NSA and its oversight of computer usage?

Bill Gates: This is a complex issue. Privacy will be increasingly important as cameras and GPS sensors are gathering information to try and be helpful. We need to have trust in the way information is protected and gathered. There is a role for the government to try and stop crime and terrorism but it will have to be more open. I do think terrorism with biological or nuclear weapons is something we want to minimize the chance of.

Q: What are your thoughts about cryptocurrencies like Bitcoin?

A: The [Bill & Melinda Gates Foundation] is involved in digital money but unlike Bitcoin it would not be anonymous digital money. In Kenya M-pesa is being used for almost half of all transactions. Digital money has low transaction costs which is great for the poor because they need to do financial transactions with small amounts of money. Over the next 5 years I think digital money will catch on in India and parts of Africa and help the poorest a lot.

Q: You’re working with TerraPower to bring a large scale source of low-carbon energy onto the commercial grid. What, in your opinion, is the biggest impediment to bringing new nuclear technology onto the global market?

A: We need low cost energy that is totally reliable. Most renewables will require storage which is expensive to do this. Nuclear will make a contribution if we can make it safer, cheaper and deal with waste better. Terrapower has a design (on paper) that addresses all of these issues so now we are talking to countries about building it. It is a 4th generation reactor design that uses depleted uranium.

Q: Any luck with the condom design competition?

A: This is a sensitive topic. The idea was that men don’t like the current design so perhaps something they would be more open to would allow for less HIV transmission. We still haven’t gotten the results. One grantee is using carbon nanotubes to reduce the thickness.

Q: What smartphone and/or tablet are you currently using?

A: I am using a Surface 2 PRO which works well for me.

Q: What is the worst case that you know of where your philanthropy backfired?

A: A lot of our failures have been backing science that didn’t work out. One thing that is tough is when you think the government will take over something you start but they don’t — we had that with a school lunch program. It might have been better if we hadn’t done it.