Andy Yen is founder and CEO of tech company Proton, best known for its encrypted email service Proton Mail.He was born in Taiwan, studied in California, then moved to Switzerland to work at CERN as a particle physicist. He then set up Proton from Geneva.Dougal Shaw talks to the entrepreneur about growing up in the shadow of China, personal privacy in an age when we live our lives online, and his company’s “cat and mouse” games with Russia over VPN software, which allows people to access the internet without state control.(Picture: Andy Yen)Presented and produced by Dougal Shaw