Why I Wrote PGP (1991, revised 1999)

Phil Zimmermann explains that he created PGP to protect private electronic communications as telecommunications and the Internet made routine mass surveillance possible. He outlines how phones and email transformed private conversations into data that can be scanned and stored, and cites specific U.S. developments that expanded surveillance capabilities: a proposed 1991 Senate resolution urging backdoors, the CALEA mandate for remote wiretapping ports, FBI plans to sample one percent of urban phone calls, and the Clipper chip key-escrow scheme. Historical abuses such as COINTELPRO, Nixon’s enemies list, and Watergate demonstrate governmental incentives to exploit entrenched surveillance infrastructure.

Zimmermann argues that strong, widely used cryptography is the only practical defense: universal encryption provides safety in numbers and makes criminalization politically difficult. He published PGP freely to encourage widespread adoption and to oppose key-escrow and export-control policies. Public pressure and deployment contributed to the 1999 reversal of U.S. export restrictions on cryptography, but domestic legal and political battles over surveillance continue. PGP empowers individuals, businesses, and dissidents to resist mass surveillance and preserve democratic freedoms; continued deployment of strong crypto is necessary to blunt expanding surveillance infrastructures.