|Born||1950 (age 72–73)|
|Alma mater||Massachusetts Institute of Technology (B.S., 1972)|
Harvard University (M.S., 1975; Ph.D., 1977)
|Known for||Coppersmith–Winograd algorithm|
|Awards||RSA Award for Excellence in Mathematics|
|Thesis||Deformations of Lie Groups and Lie Algebras (1977)|
|Doctoral advisor||John H. Hubbard|
Don Coppersmith (born c. 1950) is a cryptographer and mathematician. He was involved in the design of the Data Encryption Standard block cipher at IBM, particularly the design of the S-boxes, strengthening them against differential cryptanalysis. He also improved the quantum Fourier transform discovered by Peter Shor in the same year (1994). He has also worked on algorithms for computing discrete logarithms, the cryptanalysis of RSA, methods for rapid matrix multiplication (see Coppersmith–Winograd algorithm) and IBM's MARS cipher. He is also a co-designer of the SEAL and Scream ciphers.
In 1972, Coppersmith obtained a bachelor's degree in mathematics at the Massachusetts Institute of Technology, and a Masters and Ph.D. in mathematics from Harvard University in 1975 and 1977 respectively. He was a Putnam Fellow each year from 1968–1971, becoming the first four-time Putnam Fellow in history. In 1998, he started Ponder This, an online monthly column on mathematical puzzles and problems. In October 2005, the column was taken over by James Shearer. Around that same time, he left IBM and began working at the IDA Center for Communications Research, Princeton.
- Coppersmith, Don (May 1994). "The Data Encryption Standard (DES) and its strength against attacks" (PDF). IBM Journal of Research and Development. 38 (3): 243–250. doi:10.1147/rd.383.0243. Archived from the original (PDF) on 2009-03-25.
- Coppersmith, D. (1994). "An approximate Fourier transform useful in quantum factoring". Technical Report RC19642, IBM.
- "Putnam Competition Individual and Team Winners". Mathematical Association of America. Retrieved December 13, 2021.
- "Welcome to our monthly puzzles". Retrieved 2018-01-05.
The current puzzlemaster is Oded Margalit. He took over from James B. Shearer, who took over from the original puzzlemaster Don Coppersmith, in October 2005.
- Coppersmith, Don; Wu, Chai Wah (2008-12-01). "Conditions for weak ergodicity of inhomogeneous Markov chains". Statistics & Probability Letters. 78 (17): 3082–3085. doi:10.1016/j.spl.2008.05.012.
- "Don Coppersmith Wins RSA Security Award for Mathematics". 2002-02-19. Archived from the original on 2017-01-27. Retrieved 2018-01-05.
- "RSA Security Announces 2002 Award Recipients; Awards Recognize Major Contributions in Mathematics, Public Policy and Industry". 2002-02-19. Archived from the original on 2018-01-05. Retrieved 2018-01-05.