ure out ways to keep him at Stanford.
I found a small amount of money in a
research grant that I could use. A lot of
good things came of that.
Among them was a vigorous critique
of the Data Encryption Standard
(DES), a symmetric-key algorithm de-
veloped at IBM.
HELLMAN: DES came full-blown from
the brow of Zeus. “Zeus,” in this case,
was NBS, the National Bureau of Standards, or NSA, the National Security
Agency, or IBM, or some combination.
They didn’t tell us how they had come
DIFFIE: I was staying with Leslie
HELLMAN: I think I set up a half-hour
meeting in my office, which went on for
probably two hours, and at the end of it, I
said, “Look, I’ve got to go home to watch
my daughters, but can we continue this
there?” Whit came to our house and we
invited him and his wife, Mary, to stay for
dinner, and as I remember we ended the
conversation around 11 o’clock at night.
The two of you worked together for the
next four years.
HELLMAN: Whit had been traveling
around the country and I tried to fig-
LIKE MANY DEVELOPMENTS we now
take for granted in the history of the
Internet, public key cryptography—
which provides the ability to communicate securely over an insecure
channel—followed an indirect path
into the world. When ACM A.M. Turing Award recipients Martin Hellman and Whitfield Diffie began their
research, colleagues warned against
pursuing cryptography, a field then
dominated by the U.S. government.
Their 1976 paper “New Directions in
Cryptography” not only blazed a trail
for other academic researchers, but
introduced the ideas of public-key
distribution and digital signatures.
How did you meet?
DIFFIE: In the summer of 1974, my
wife and I traveled to Yorktown Heights
(NY) to visit a friend who worked for
Alan Konheim at IBM.
You’re talking about the head of the
IBM mathematics group and author
of Cryptography: A Primer, who subsequently moved to the University of California, Santa Barbara.
DIFFIE: Konheim said he couldn’t tell
me very much because of a secrecy order, but he did mention that his friend
Marty Hellman had been there a few
months ago. He said, “I couldn’t tell
him anything either, but you should
look him up when you get back to Stanford, because two people can work on a
problem better than one.”
HELLMAN: So Whit gives me a call. Whit,
you were up in Berkeley at the time?
DOI: 10.1145/2911977 Leah Hoffmann
Finding New Directions
Whitfield Diffie and Martin Hellman on their meeting,
their research, and the results that billions use every day.
[CONTINUED ON P. 110]