# Richard Crandall

**Richard E. Crandall** (December 29, 1947 - December 20, 2012) was an American computer scientist and physicist who has made contributions to computational number theory. He received a doctorate from Massachusetts Institute of Technology.

He is notable for the development of the Irrational base discrete weighted transform (IBDWT), a special form of FFT. It halves the required FFT lengths for Lucas-Lehmer squaring. IBDWT is used in programs such as Prime95, CUDALucas, Glucas and gpuLucas.

He has, at various times, been Chief Scientist at NeXT Inc. (which was purchased by Apple) and Apple's Chief Cryptographer. He was Vollum Adjunct Professor of Science and director of the Center for Advanced Computation at Reed College at the time of his death. He has been awarded numerous patents for his work in the field of cryptography.

His Erdös number is 2. He was one of the primary verifiers of M32, M33, and M34.

In 1997 he founded a consulting firm, Perfectly Scientific, Inc., dedicated to industrial algorithm design. Perfectly Scientific has, since 1999, made available for purchase posters of the largest known Mersenne prime numbers. Posters of M38, M39, M40, M41, M42, M43, M44, M45, and M47 were available.

He fronted a band called the Chameleons in 1981.

## Contents

## Articles

- R. Crandall, B. Fagin. "Discrete weighted transforms and large-integer arithmetic" (1994)
- R. Crandall. "Integer convolution via split-radix fast Galois transform" (1999)
- R. Crandall, E. Jones, J. Klivington, and D. Kramer. Gigaelement FFTs on Apple G5 clusters. Advanced Computation Group, Apple Computer. 27 Aug 2004.

## Books

*Pascal Applications for the Sciences.*John Wiley & Sons, New York 1983.- with M. M. Colgrove:
*Scientific Programming with Macintosh Pascal*. John Wiley & Sons, New York 1986. *Mathematica for the Sciences*, Addison-Wesley, Reading, Mass, 1991.*Projects in Scientific Computation.*Springer 1994.*Topics in Advanced Scientific Computation.*Springer 1996.- with M. Levich:
*A Network Orange.*Springer 1997. - with Carl Pomerance:
*Prime numbers: A Computational Perspective.*Springer 2001.