Conference article

Dead Ends in Breaking an Unknown Cipher: Experiences in the Historiography of the Rohonc Codex

Benedek Láng
Budapest University of Technology and Economics, Hungaria

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Published in: Proceedings of the 2nd International Conference on Historical Cryptology, HistoCrypt 2019, June 23-26, 2019, Mons, Belgium

Linköping Electronic Conference Proceedings 158:6, p. 51-57

NEALT Proceedings Series 37:6, p. 51-57

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Published: 2019-06-12

ISBN: 978-91-7685-087-9

ISSN: 1650-3686 (print), 1650-3740 (online)


A close reading of unsuccessful breaking attempts of unsolved historical cryptograms (particularly, if they happened to be solved at a later moment) is more useful than it would be obvious at first glance. While the specific offered by code breakers differ from each other, the attempts in the case of the Rohonc Codex, the Voynich manuscript, and other historical ciphers (or codes) exhibit surprising structural similarities. These attempts can be classified into promising and unpromising subcategories on structural grounds even when the final solution is not available. The paper aims at supporting this argument in a case study of the of the Rohonc Codex, which include an old-Hungarian, a proto-Rumanian (11th Sanskrit script theory. A more convincing thread also emerges, details of which are in the process of being published.

This work has been supported by the Swedish Research Council, grant 2018-06074, DECRYPT - Decryption of historical manuscripts.


historical cryptograms the Rohonc Codex code breaking


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