Law enforcement officials generally aren’t fans of what’s called end-to-end encryption — messages that can only be read by the sender and the recipient. They call it “going dark” and argue that encrypted communications make it harder to investigate or uncover crimes. Host Molly Wood spoke with Moxie Marlinspike, founder and CEO of the private chat app Signal Messenger, about what a ban on encryption — or giving law enforcement a back door to messages — might mean.