A programmer with an engineering degree from Caltech, in 1991 Finney heard about a programming effort called “Pretty Good Privacy” — or PGP, a way to encrypt e-mails to ensure their privacy, and to “sign” the message so that the recipient could know it hadn’t been altered. Finney, who specialized in cryptology, volunteered to help develop it. When PGP creator Phil Zimmerman created a company to commercialize the software, Finney was the first developer he hired. “Hal was motivated by the highest ideals of human rights,” Zimmermann says, particularly the fundamental right of privacy. Or, as Finney himself put it: “The work we are doing here, broadly speaking, is dedicated to this goal of making Big Brother obsolete.”
Finney was also interested in the “digital currency” Bitcoin, which is not tied to any national monetary unit; he was the first person to be paid for something in Bitcoins (10 of them, sent by Bitcoin creator “Satoshi Nakamoto”). Finney went on to work on increasing the security of the Bitcoin system software. But in 2009, Finney learned he had amyotrophic lateral sclerosis — ALS, or “Lou Gehrig’s disease” — which slowly robbed him of his ability to move. He continued to work as long as he could, writing Bitcoin-related software using an eye-tracker to communicate with his computer. “I’m pretty lucky overall,” he wrote on a Bitcoin forum last year. “Even with the ALS, my life is very satisfying. I’m comfortable with my legacy.” He was hospitalized, completely paralyzed, and per his wishes, he was removed from life support and died at the hospital in Scottsdale, Ariz., on August 28. He was 58.