• 1932 July 25
    (b.) -
    2011 June 26


An American cryptographer and computer scientist, he was born in Boston, Massachusetts. He received a Bachelor's Degree in Mathematics from Harvard University in 1957 and a Master's Degree in Applied Mathematics from Harvard in 1958. From 1960 until 1986, he was a researcher at Bell Labs and worked on Multics and later UNIX. His contributions to early versions of UNIX include the math library, the program crypt, and the password encryption scheme used for user authentication. The encryption scheme was based on using a trapdoor function (now called a key derivation function) to compute hashes of user passwords which were stored in the file /etc/passwd; analogous techniques, relying on different functions, are still in use today. In 1986, he began work at the National Security Agency (NSA). He served as chief scientist of the NSA's National Computer Security Center, where he was involved in the production of the Rainbow Series of computer security standards, and retired from the NSA in 1994. He once told a reporter that, while at the NSA, he helped the FBI decode encrypted evidence. There is a description of him in Clifford Stoll's book The Cuckoo's Egg. Many readers of Stoll's book remember him for giving Stoll a challenging mathematical puzzle (originally due to John H. Conway) in the course of their discussions on computer security: What is the next number in the sequence 1 11 21 1211 111221? (known as the look-and-say sequence). Stoll chose not to include the answer to this puzzle in The Cuckoo's Egg, to the frustration of many readers.
  • Date of Birth:

    1932 July 25
  • Date of Death:

    2011 June 26
  • Gender:

  • Noted For:

    Contributor to early versions of UNIX which included the math library, the program crypt, and the password encryption scheme used for user authentication
  • Category of Achievement:

  • More Info: