“Many of the breakthroughs we've had in society began as fool's errands,” says cryptologist and computer scientist Martin Hellman. He ought to know. When he entered the still-emerging field of cryptography in the 1970s, it was seen as a ludicrous career choice. The NSA had a stranglehold on relevant research, and any really interesting work seemed bound to be classified.
It's a good thing for all of us that Hellman played the fool. Along with Whitfield Diffie and Ralph Merkle, he invented something called “public key cryptography.” You might not know the term, but it's at the center of your daily life. Without public key encryption, there could be no electronic banking, no online shopping, no secure instant messaging. It's what keeps your digital exchanges safe from third-party interference.
Hellman's success came with personal risk. For one thing, his early publications roused the NSA, and there were calls for his incarceration. But he foresaw a public need, and helped erect a paradigm that supports literally billions of people. And while his many accolades include the Turing Award — the most prestigious prize in computer science — public key cryptography doesn't completely define him. Hellman has also worked for decades, as a writer and an activist, to promote global security and nuclear disarmament. “Because what good are cryptographic algorithms,” he asks, “if there is no one here to use them?”