__Lester S. Hill__

Born: 1861

Death: 1961

Born in New York, Lester S. Hill was a mathematician and educator. After graduating from Colombia University and obtaining his PhD at Yale University, he continued to involve himself in education.

He devoted his life to teaching mathematics and astronomy at five different schools across the United States. He was also very implicated in the military and was highly praised by the US government for his many results in modular algebraic ciphers and codes that he shared with the Army before and during World War II.

Hill was interested in the application of advanced mathematics to communications and developed many methods to breaking errors in telegraphed communications. He was notably one of the biggest contributors of cryptology; the art of making and breaking codes and ciphers. In 1929, he invented Hill ciphers which were polygraphic substitution ciphers founded on linear algebra. Matrices and matrix multiplication were used to encrypt and decrypt the plaintext. Hill also created a cipher machine that relied on a system of wheels and chains.

Throughout his life, he continuously applied his knowledge of mathematics to design and decode crypto systems. He died, in New York, at the age of 70, from an unknown illness.

Death: 1961

Born in New York, Lester S. Hill was a mathematician and educator. After graduating from Colombia University and obtaining his PhD at Yale University, he continued to involve himself in education.

He devoted his life to teaching mathematics and astronomy at five different schools across the United States. He was also very implicated in the military and was highly praised by the US government for his many results in modular algebraic ciphers and codes that he shared with the Army before and during World War II.

Hill was interested in the application of advanced mathematics to communications and developed many methods to breaking errors in telegraphed communications. He was notably one of the biggest contributors of cryptology; the art of making and breaking codes and ciphers. In 1929, he invented Hill ciphers which were polygraphic substitution ciphers founded on linear algebra. Matrices and matrix multiplication were used to encrypt and decrypt the plaintext. Hill also created a cipher machine that relied on a system of wheels and chains.

Throughout his life, he continuously applied his knowledge of mathematics to design and decode crypto systems. He died, in New York, at the age of 70, from an unknown illness.

## References

Eisenberg, M. (1999, November 3). Hill Ciphers and Modular Linear Algebra. Apprendre en ligne. Retrieved March 13, 2012, from www.apprendre-en-ligne.net/crypto/hill/Hillciph.pdf

Lester S. Hill. Wikipedia. Wikipedia Foundation Inc., 5 Aug. 2012. Web. 13 Mar. 2013. en.wikipedia.org/wiki/Lester_S._Hill

Lyons, J. Practical Cryptography. Practical Cryptography. Retrieved March 13, 2013, from http://practicalcryptography.com/ciphers/hill-cipher/

Morain, F. (1997, April 21). A History of Cryptology. Algorithms Project's Home Page. Retrieved March 13, 2013, from http://algo.inria.fr/seminars/sem96-97/morain.html

New York Times. Lester Hill Dies; A Mathematician. Middlebury. New York Times, 10 Jan. 1961. Web. 13 Mar. 2013. http://w10.middlebury.edu/INTD1065A/Lectures%20%20folder/Hill%20Cipher%20Folder/Lester_Hill046.pdf

Lester S. Hill. Wikipedia. Wikipedia Foundation Inc., 5 Aug. 2012. Web. 13 Mar. 2013. en.wikipedia.org/wiki/Lester_S._Hill

Lyons, J. Practical Cryptography. Practical Cryptography. Retrieved March 13, 2013, from http://practicalcryptography.com/ciphers/hill-cipher/

Morain, F. (1997, April 21). A History of Cryptology. Algorithms Project's Home Page. Retrieved March 13, 2013, from http://algo.inria.fr/seminars/sem96-97/morain.html

New York Times. Lester Hill Dies; A Mathematician. Middlebury. New York Times, 10 Jan. 1961. Web. 13 Mar. 2013. http://w10.middlebury.edu/INTD1065A/Lectures%20%20folder/Hill%20Cipher%20Folder/Lester_Hill046.pdf