He wrote a precedent-breaking book on Cryptography. He didn't write it because he was a cryptographer, he wrote it because he dared to do so when a lot of other people were afraid to do so. Out of this, he established a punditry that allows him to pretend to be a 'smart cryptography expert.' Sometimes he's even billed as a 'security expert.' But really he's a popular writer who writes for nerds. Not an expert who could contribute a solution.