Étienne Bazeries

Étienne Bazeries was a French military cryptanalyst active from the late nineteenth century through the First World War. He became known for practical codebreaking and for a cylindrical cipher device that bears his name.

Cryptanalysis and devices

Bazeries demonstrated weaknesses in official cipher practice and developed the Bazeries cylinder, a device related in concept to the Jefferson cylinder and later U.S. Army cylinder-cipher equipment. Historical accounts also associate him with successful work on the Great Cipher of Louis XIV.

Practical cryptology

His career captures a recurring security pattern: operational systems are tested by determined analysts, and their shortcomings motivate new designs.

In memoriam

Bazeries died in 1931. His work remains a landmark in the history of French military cryptology.

Timeline

• 1846-08-21Born in Port-Vendres, France.
• 1890Identifies weaknesses in a French military cipher system.
• 1891Develops the cylindrical cryptograph later called the Bazeries cylinder.
• 1901Publishes Les Chiffres Secrets Dévoilés.
• 1931-11-07Dies in Noyon, France.