Displays the cryptography machine that Leibniz developed in the 1670's, together with related scholarly material, such as Nicholas Rescher's book on Leibniz as cryptographer and historical documents.

The exhibit *Leibniz as Cryptographer * is on display until December 21st, 2013 in the Special Collections Reading Room in Room 363 Hillman Library. The exhibit is free and open to the public during the deparment's regular hours: Monday-Friday, 9am-4:45pm.

**Special Collections Department**

A&SC at Hillman Library

3960 Forbes Avenue

Pittsburgh, PA 15260

**Phone**: 412-648-8190

**Email**: ULS-Archives&SpecialCollections@pitt.edu

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The exhibit is based on a book entitled Leibniz and Cryptography by Nicholas Rescher.

The book presents a discussion of Leibniz's interest in cryptographical mathematics.

Gottfried Wilhelm Leibniz

1646-1716

Gottfried Wilhelm Leibniz, a German polymath, was born in 1646 and died in 1716. He was one of the greatest mathematicians and philosophers of his time. He independently invented the mathematical discipline now known as the calculus, sharing that distinction with Sir Isacc Newton. Leibniz also made important contributions to many other fields of science, philosophy and mathematics. He made contributions to geology, historiography, physics, and library science among other disciplines. Leibniz also worked as a diplomat for such employers as the Elector of Hanover and the Elector of Mainz. He combined his work as a diplomat with his interest in mathematics by considering problems in encryption and ciphering. Among the results was the ciphering machine on display.

*Leibniz as Cryptographer* features the only working model ever constructed of the cryptography machine conceived of in the late 17th Century by Leibniz. This machine uses certain structures and methods similar to his calculating machine, versions of which were built in his lifetime. One of the most important elements in the mechanical functioning of the machine was the staffelwalze or stepped drum. There is a short digital film that illustrates the functioning of the stepped drum on the Multimedia page.

Nicholas Rescher with the cipher machine that was constructed as part of his research into Leibniz''s interest in Cryptography and the mathematics of cryptography.

The source of the information needed to recreate the machine came from a prospectus sent by Leibniz to the government of the Holy Roman Emperor Leopold I as well as from information about the structure and functioning of Leibniz's calculation machine which could add, subtract, multiply and divide numbers. Professor Rescher used the prospectus to conceptually recreate the machine. To then make the functional version of the cipher machine that is on display he worked with craftsmen and engineers at a firm in Hannover, Germany that has specialized in reconstructing historically important scientific machines.

Lance Lugar

347 Hillman Library

412-648-8196

lugar@pitt.edu

412-648-8196

lugar@pitt.edu

The Stanford Encyclopedia of Philosophy Online has a most useful article on Leibniz as well as an extensive array of articles on topics that interested Leibniz and to which he made important contributions

In addition there are several archives which have substantial holdings of Leibniz related materials. One of the most important is the extensive collection of letters and other materials held at the Leibniz Research Center in Hannover in Germany.