This electronic thesis or dissertation has been downloaded from Explore Bristol Research, http://research-information.bristol.ac.uk Author: Diepenbroek, Martine L M Title: Myths and Histories of the Spartan scytale A comprehensive review and reassessment of the extant sources describing the cryptographic Spartan device known as the scytale to challenge the view promoted by modern historians of cryptography that denies the scytale its deserved status as a vehicle for secret communication in the ancient world General rights Access to the thesis is subject to the Creative Commons Attribution - NonCommercial-No Derivatives 4.0 International Public License. A copy of this may be found at https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode This license sets out your rights and the restrictions that apply to your access to the thesis so it is important you read this before proceeding. 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Myths and Histories of the Spartan scytale A comprehensive review and reassessment of the extant sources describing the cryptographic Spartan device known as the scytale to challenge the view promoted by modern historians of cryptography that denies the scytale its deserved status as a vehicle for secret communication in the ancient world Martine Loekie Mariska Diepenbroek A dissertation submitted to the University of Bristol in accordance with the requirements for the award of the degree of Doctor of Philosophy in the Faculty of Arts School of Humanities Department of Classics and Ancient History Date of submission: January 2020 Word count: 69.727 (excluding footnotes, references, and appendices) Abstract The current study is a comprehensive review and reassessment of the extant sources describing the cryptographic Spartan device known as the scytale, to challenge the view promoted by modern historians of cryptography that denies the scytale its deserved status as a vehicle for secret communication in the ancient world. Modern historians of cryptography see the scytale essentially as a simple ‘stick’ that would have served little practical use as a vehicle for secret communication. Yet, this study seeks to demonstrate that the cryptographic principles employed in the Spartan scytale show an encryption and coding system that is no less complex than some 20th century transposition ciphers. It will be shown that, contrary to the accepted point of view, scytale encryption is as complex and secure as other known ancient ciphers. The study will draw salient comparisons with a selection of modern transposition ciphers (and their historical predecessors), and offer a detailed review and comprehensive new analysis of the surviving classical sources that similarly reveal the potential of the scytale as an actual cryptographic tool in ancient Sparta in order to illustrate the relative sophistication of the Spartan scytale as a practical device for secret communication. This helps to establish the conceptual basis that the scytale would, in theory, have offered its ancient users a potentially secure method for secret communication – particularly over long distances. The study will be complemented by two appendices to the work in which an overview is given of all surviving ancient literary sources on cryptography and steganography as well as an overview of all extant medieval, Renaissance, and modern sources referring back to these classical sources, making this study the most comprehensive collection of Greek and Roman cryptographic and steganographic sources created so far – and thereby making an original and significant contribution to the current scholarship on the ancient history of cryptography. 2 Dedication and acknowledgements My thanks and appreciation to my supervisors at the University of Bristol. First, many thanks to Professor Neville Morley, who supervised me during my first year, and who helped me to start the research, and to create a plan to make it possible to finish the research and dissertation within the duration of the course. Secondly, many thanks to Dr. Genevieve Liveley who became my supervisor at the end of the first year, and who helped me to get through my upgrade process. Your enthusiasm, support, and valuable comments have been a major help throughout the duration of the course. It certainly improved my writing and research skills in many ways. My thanks also go to Dr. Isabella Sandwell for acting as my second supervisor throughout the duration of the course, to Professor Patrick Finglass for proofreading various drafts of the dissertation and especially for his invaluable suggestions on Herodotus. I also thank Dr. Amy Coker for being my upgrade assessor at the end of the first year. Many thanks and appreciation also to Dr. John Black, an independent historian and researcher, for acting as my advisor and for proofreading parts of the dissertation throughout the time it took me to complete this research and to write the dissertation. Finally, on a more personal note, I would like to thank everyone at the Bristol International Student Centre (BISC) with whom I worked during my Ph.D. years in Bristol next to my studies. Thank you all for being great friends who always supported me, and for often enquiring after my research and my personal well-being! Special thanks go to Eve Scott for proofreading the final draft and for being a great friend over the years. And most importantly, this dissertation is dedicated to my parents who have always been extremely supportive in countless ways, since I was a little girl. You have always believed that studying Classics and Ancient History was an excellent choice for me, and I agree. Therefore, this work 3 is for you. I am very grateful for the support and help that I have received from every one of you. Otherwise, I would not have been able to complete my research degree. 4 Author’s declaration I declare that the work in this dissertation was carried out in accordance with the requirements of the University’s Regulations and Code of Practice for Research Degree Programmes and that it has not been submitted for any other academic award. Except where indicated by specific reference in the text, the work is the candidate’s own work. Work done in collaboration with, or with the assistance of, others, is indicated as such. Any views expressed in the dissertation are those of the author. The prologue of the thesis is based on a publication on part of the research: Diepenbroek, M. L. M. (2019). From Fire Signals to ADFGX. A case study in the Adaptation of Ancient Methods of Secret Communication. KLEOS - The Amsterdam Bulletin of Ancient Studies and Archaeology, 63-76. References to the publication are also made in chapters 3 and 5. SIGNED: DATE: 5 Table of Contents Abstract ................................................................................................................................................... 2 Dedication and acknowledgements ......................................................................................................... 3 Author’s declaration ................................................................................................................................ 5 Table of Contents .................................................................................................................................... 6 List of tables and illustrative material ..................................................................................................... 9 Introduction ........................................................................................................................................... 11 Working definitions: steganography and cryptography .................................................................... 15 Overview ........................................................................................................................................... 17 Review of literature ........................................................................................................................... 19 Research methodology ...................................................................................................................... 32 Prologue ................................................................................................................................................ 35 Chapter 1: Ancient steganography: Herodotus’ contributions .............................................................. 51 1.1: Ancient cryptography and steganography ................................................................................. 52 1.1.1: Bellerophon’s tablet ............................................................................................................ 54 1.2: Secret communication in Herodotus’ Histories