Richard Schroeppel

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Richard Schroeppel (2004)

Richard C. Schroeppel (* 1948 near Chicago in Illinois ) is an American computer scientist and mathematician who deals with algorithmic number theory and cryptography .

Schroeppel studied at MIT , where he made his bachelor's degree in 1968. In 1966 and 1967 he was a Putnam Fellow there. From 1991 to 1998 he conducted research on computer security issues at the University of Arizona . He currently works at Sandia National Laboratories .

Schroeppel, together with Michael Beeler and Ralph William (Bill) Gosper, was co-author of the famous "Artificial Intelligence Memo" HAKMEM (AIM-239 from MIT) on February 29, 1972. Later he discovered the sub-exponential running time of some factorization algorithms such as the continued fraction method , which he was then able to improve (method of the linear sieve ). After Carl Pomerance , his ideas, which he often did not publish, played a role in the development of the factoring algorithm of the square sieve by Pomerance himself and also in the number field sieve .

In the 1970s he worked with Whitfield Diffie and Martin Hellman at Stanford on analyzing the security of DES .

In 1998/99 he developed the Hasty Pudding Cipher as a candidate in the competition for the AES cryptography standard .

He also dealt with entertainment mathematics and determined, for example, the number of magic squares with a side length of 5.

Web links

Individual evidence

  1. ↑ HAKMEM at answers.com
  2. ↑ End of the 1970s, not published, but z. B. discussed by Carl Pomerance, Analysis and comparison of some integer factoring algorithms , in Lenstra, Tijdeman (Ed.): Computational Methods in Number Theory , Math. Centrum Tracts Vol. 154, Amsterdam, 1982, p. 89
  3. ↑ Pomerance: A tale of two sieves , Notices AMS, December 1996, p. 1477 calls Schroeppel's linear sieve a forerunner and the inspiration for his square sieve
  4. ^ Pomerance: A tale of two sieves , Notices AMS, December 1996, p. 1479, suggestion for John M. Pollard was a discrete logarithm algorithm with quadratic number fields by Coppersmith, Schroeppel, Odlyzko: Discrete logarithms in GF (p) , Algorithmica, Vol. 1, 1986, pp. 1-15
  5. ^ Diffie, Hellman, Merkle, Schroeppel, L. Washington, S. Pohlig, P. Schweitzer: Results of an initial attempt to cryptanalysis the NBS Data Encryption Standard , Technical Report SEL 76-042, Information Systems Lab, Department of Electrical Engineering, Stanford University 1976
personal data
SURNAME Schroeppel, Richard
ALTERNATIVE NAMES Schroeppel, Richard C.
BRIEF DESCRIPTION American mathematician
DATE OF BIRTH 1948
PLACE OF BIRTH near Chicago