Identifying concealed messages using authorship attribution

Abstract

Letter-based concealments are often used by criminals to exchange secret messages without attracting the attention of law enforcement. This paper presents a method of distinguishing an author’s writing style when employing a concealment from the author’s writing style when writing naturally.

Keywords:

• Authorship attribution
• concealment
• forensics
• null cipher
• open code

Acknowledgments

The author would like to thank the members of the Cryptanalysis and Racketeering Records Unit of the FBI Laboratory for all of their helpful ideas and feedback.

Additional information

Notes on contributors

Kirsten Tate

Kirsten Tate is an Honors Intern in the Cryptanalysis and Racketeering Records Unit (CRRU) of the FBI Laboratory. She is studying Mathematics and Computer Science at Randolph-Macon College and will be joining CRRU as a Cryptanalyst Forensic Examiner following her graduation.