Phil Zimmermann is an American cryptographer and computer scientist best known for creating Pretty Good Privacy (PGP), a data encryption program that provides cryptographic privacy and authentication. He developed PGP in 1991 to enable individuals to secure their communications and protect their personal information from unauthorized access. Zimmermann's work has had a significant impact on digital privacy and security, influencing how people protect their data online. His commitment to privacy rights has made him a prominent figure in discussions about encryption, cybersecurity, and the balance between government surveillance and individual freedoms.