Kaczynski's Ciphers

Abstract

A child prodigy and Harvard University graduate turned serial killer, Theodore Kaczynski—now better known as the Unabomber—constructed elaborate cipher systems to encrypt his thoughts and emotions. His personal journals contain enciphered details of his life, his beliefs and feelings about society, and his crimes. This article introduces the Unabomber's cipher systems and through his use of these systems gives a brief glimpse into a fascinating mind that crossed the line between genius and madness.

Keywords:

• additive cipher
• cryptanalysis
• Cryptanalysis and Racketeering Records Unit
• FBI
• matrix
• route
• serial killer
• Theodore Kaczynski
• Unabomber

Acknowledgements

This is publication 14-07 of the Laboratory Division of the FBI. The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the FBI or the U.S. Government. This work was prepared as part of their official duties. Title 17 U.S.C. 105 provides that “copyright protection under this title is not available for any work of the United States Government.” Title 17 U.S.C. 101 defines a United States Government work as a work prepared by an employee of the United States Government as a part of that person's official duties.

The author gratefully acknowledges the work and knowledge of Mike Birch, the FBI cryptanalyst who painstakingly worked on cryptanalyzing the journals after their seizure in 1996.

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Notes on contributors

Jeanne Anderson

Jeanne Anderson studied mathematics and economics at Georgetown College and Oxford University. She is currently a cryptanalyst in the Cryptanalysis and Racketeering Records Unit of the FBI.