Bruce Schneier is the Bill Nye of computer security. He has made a career of both as a cryptographer and as someone who can make computer security issues accessible. I've been reading his works for over twenty years. I fought to have has first book Applied Cryptography used as a text when I was in my third year in college. In his field, he is an absolute heavyweight. He is also a noted civil libertarian on privacy issues and a board member of the Electronic Frontier Foundation, which for the unfamiliar, is the ACLU of the internet.