June 5, 1991
Phil Zimmermann releases PGP
Phil Zimmermann released Pretty Good Privacy (PGP) 1.0 on June 5, 1991 — bringing public-key email encryption to activists and developers.
What it was for
PGP let anyone encrypt email and files without a central authority — using RSARivest–Shamir–Adleman — a widely used public-key encryption algorithm named after its inventors. and IDEA in the first release. Zimmermann's export investigation made encryption policy a mainstream developer issue and paved the way for OpenPGP standards.
People
- Phil Zimmermann — creator
Why it's here
PGP democratized strong cryptography for ordinary computer users.
Why it mattered
It proved end-to-end encryption could spread via grassroots distribution, not only government or corporate channels.
What it solved
Email traveled in plaintext and proprietary crypto tools were unavailable to the public.
Media
ImagePhil ZimmermannPRZ_closeup.jpg: User Matt Crypto on en.wikipedia derivative work: Beao, CC BY-SA 3.0, via Wikimedia Commons