Unix Insider: The opening of secrets – Steven Levy recounts the history of public key cryptography

“Crypto shows us cryptography’s 30-year journey from the secret
world of the National Security Agency (NSA) to the world at large.
The journey begins in the early 1970s with Whitfield Diffie, a
misfit MIT student who felt the need to keep his private
information secret and went on a quixotic search for technology
that would let him do so. His search took him across the country to
Stanford, where he met math professor Martin Hellman.”

“Levy is careful to emphasize just how revolutionary public key
encryption was. The very idea that ordinary citizens could protect
their information and send it over a network gave the intelligence
and law enforcement communities the heebie-jeebies. The CIA
intercepted communications to sniff out terrorists and steal
secrets from the Soviets, and the FBI did so to track down drug
dealers and child pornographers. Giving everyday people the ability
to keep their communications secret would be like taking away the
agencies’ ability to bug and wiretap. Scandalous.”

“If the NSA had its way, private citizens would not be allowed
to use cryptography. But in the 1960s, researchers from IBM
developed an algorithm to give the technology to the company’s many
corporate customers. The NSA tried to stifle IBM’s invention. After
much negotiation, IBM agreed to relinquish control of the
technology to the NSA in exchange for financial consideration and
the agency’s imprimatur. The result was the Data Encryption
Standard (DES), which IBM and others began to build into their
products.”

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