The self-identified anarchist, sailor, and ex-head of Twitter’s security team captains a crew of coders that has developed what many experts deem to be the best encryption tools on the planet. Marlinspike (yes, his name is a pseudonym), a dreadlocked hacker and founder of the small San Francisco-based non-profit Open Whisper Systems, has devised data-jumbling schemes that secure people’s digital conversations from the prying eyes of hackers and spies—while controversially frustrating law enforcement and intelligence agency investigations. This year WhatsApp, Facebook Messenger, and Google’s Allo all baked his crypto protocols into their messaging apps, battening down the communications of more than a billion people worldwide.