Alchemical ciphers

In 2021, I was involved in the decryption of a sophisticated alchemical cipher in a shared notebook by John and Arthur Dee.

After my involvement in the decryption of an alchemical cipher (Bean et al., 2021), I have developed expertise in alchemical ciphers and the broader historical and epistemic context of what might be called “occult cryptography.” Because practitioners of some so-called “occult sciences”, including alchemy and astrology, sometimes employed highly sophisticated cryptographic techniques, I contend that this tradition developed independently from diplomatic cryptography, pursuing distinct goals and following its own historical trajectory.

In 2021, my collaborators and I decrypted a rare and highly sophisticated early modern alchemical cipher (Bean et al., 2022) — one of the most advanced techniques of its time, and a rare and early instance of the famous Vigenère type found “in the wild” rather than in cipher handbooks (Lang & Piorko, 2021).

A separate contextual study appeared in Ambix (Piorko et al., 2023), focusing on the cipher’s material form, its association with the figures of John and Arthur Dee, and its place within alchemical cultures of secrecy (Lang, 2023).

Our story was picked up by the media and adapted into a play by French playwright Benoit Solès, Le secret des secrets (Paris 2025).

In the meantime, I have further explored the intersections of alchemy and cryptography more broadly (Lang et al., 2024), including investigations into Rudolf II’s alchemical handbell (Bean et al., 2023), although this has not yet led to conclusive results (Bean et al., 2023).

References

2024

Sources of Alchemical Cryptography

Sarah Lang, Sergei Zotov, and Megan Piorko

In Proceedings of the 7th International Conference on Historical Cryptology (HistoCrypt 2024), 2024

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This paper presents an initial overview of cryptographic sources relating to alchemy, an area that remains largely unexplored. Alchemists and chymists frequently encrypted short passages relating to recipes and experiments, obscured content using exotic foreign languages or custom shorthand, and created unique symbol codes. A survey of manuscripts reveals the diversity of sources in over 100 instances of ciphering in alchemical contexts, where ciphers were only one of several methods traditionally used to maintain secrecy. It serves as a starting point for further research, demonstrating the wealth of archival material related to alchemical cryptography – a goldmine yet untapped.
@inproceedings{LangZotovPiorko2024sourcesAlchCrypto, title = {Sources of Alchemical Cryptography}, author = {Lang, Sarah and Zotov, Sergei and Piorko, Megan}, booktitle = {Proceedings of the 7th International Conference on Historical Cryptology (HistoCrypt 2024)}, year = {2024}, publisher = {Tartu University Library}, doi = {10.58009/aere-perennius0105}, url = {https://dspace.ut.ee/items/2d947b3a-6246-4934-8d4e-02fb056c7992}, keywords = {alchemy, history of cryptography, alchemical ciphers, history of science, chymistry} }

2023

Deciphering the Hermeticae Philosophiae Medulla: Textual Cultures of Alchemical Secrecy

Megan Piorko, Sarah Lang, and Richard Bean

Ambix, 2023

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This article presents the decryption, historical analysis, and alchemical interpretation of an alchemical cipher found in a shared notebook of John and Arthur Dee (British Library MS Sloane 1902). The cipher is an early example of a Bellaso/Della Porta/Vigenère type, a strong encryption method which was historically deemed indecipherable. The essay explores the medical and alchemical context for the manuscript into which the cipher was copied and provides the transcription, plaintext solution (in Latin), and English translation of the encrypted text. Further, it interprets the enciphered text through the lens of alchemical practice and provides evidence for the dissemination of this cipher as part of a larger alchemical knowledge network.
@article{Lang2023Deciphering, author = {Piorko, Megan and Lang, Sarah and Bean, Richard}, title = {Deciphering the Hermeticae Philosophiae Medulla: Textual Cultures of Alchemical Secrecy}, journal = {Ambix}, year = {2023}, volume = {70}, number = {2}, pages = {150--183}, doi = {https://doi.org/10.1080/00026980.2023.2201744}, url = {https://doi.org/10.1080/00026980.2023.2201744}, keywords = {alchemy, cipher}, }
Situating ciphers among alchemical techniques of secrecy

Sarah Lang

In Proceedings of the 6th International Conference on Historical Cryptology HistoCrypt 2023, 2023

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This paper offers a contextual framework for the historical analysis of alchemical ciphers. It argues that they differ from other ciphers due to their unique context: the alchemical tradition embodies a performative culture of secrecy, which employs a variety of techniques to achieve this performance. This paper contends that the distinction between ‘secret as content’ versus ‘secrecy as practice’ presents a useful framework for understanding alchemical rhetorics of secrecy and their relationship to alchemical cryptography. Additionally, it demonstrates how these principles can be applied in interpreting several examples.
@inproceedings{Lang2023histocrypt, author = {Lang, Sarah}, title = {Situating ciphers among alchemical techniques of secrecy}, year = {2023}, editor = {Dahlke, Carola and Göggerle, Matthias}, booktitle = {Proceedings of the 6th International Conference on Historical Cryptology HistoCrypt 2023}, series = {Linköping Electronic Conference Proceedings 195}, pages = {93--104}, url = {https://ecp.ep.liu.se/index.php/histocrypt/article/view/698}, doi = {10.3384/ecp195698}, }

Seven metals, ringed with four magical inscriptions: what other secrets does the ‘Alchemical Hand Bell’ hold?

Richard Bean, Corinna Gannon, and Sarah Lang

Jun 2023

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@online{handbell2023conversation,
  author = {Bean, Richard and Gannon, Corinna and Lang, Sarah},
  title = {Seven metals, ringed with four magical inscriptions: what other secrets does the ‘Alchemical Hand Bell’ hold?},
  year = {2023},
  month = jun,
  day = {7},
  journal = {The Conversation},
  url = {https://theconversation.com/seven-metals-ringed-with-four-magical-inscriptions-what-other-secrets-does-the-alchemical-hand-bell-hold-204367}
}

The cipher of Emperor Rudolf II’s “Alchemical Hand Bell”

Richard Bean, Corinna Gannon, and Sarah Lang

In Proceedings of the 6th International Conference on Historical Cryptology HistoCrypt 2023, 2023

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We examine a cipher found inscribed in the so-called “Alchemical Hand Bell” from the Kunstkammer of Emperor Rudolf II. We provide insight into the bell’s history, a correction for an existing published transcription, perform statistical analysis of the ciphertext, and look at possible encryption methods and plaintext languages. Given the analysis, we examine the possibilities of digraphic and polyphonic ciphers and give a brief overview of how these were used in the historical context.

@inproceedings{handbell2023,
  author = {Bean, Richard and Gannon, Corinna and Lang, Sarah},
  title = {The cipher of Emperor Rudolf II’s “Alchemical Hand Bell”},
  year = {2023},
  editor = {Dahlke, Carola and Göggerle, Matthias},
  booktitle = {Proceedings of the 6th International Conference on Historical Cryptology HistoCrypt 2023},
  series = {Linköping Electronic Conference Proceedings 195},
  pages = {13--17},
  doi = {10.3384/ecp195690},
  url = {https://ecp.ep.liu.se/index.php/histocrypt/article/view/690},
  keywords = {Rudolf II, alchemy, handbell, statistical analysis, digraphic cipher, polyphonic cipher, Kunsthistorisches Museum Wien, Voynich}
}

2022

Solving an alchemical cipher in a shared notebook of John and Arthur Dee

Richard Bean, Sarah Lang, and Megan Piorko

In Proceedings of the 5th International Conference on Historical Cryptology (HistoCrypt 2022), 2022

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This paper builds on a work in progress by Lang and Piorko published in HistoCrypt 2021, which presented a seventeenthcentury ciphertext and cipher table discovered in a shared notebook of John and Arthur Dee (Sloane MS 1902). Using Latin statistical models we have successfully deciphered the encrypted text. Our results found the plaintext to consist of 177 Latin words describing a practical experiment for the creation of the alchemical Philosophers’ Stone, presented as a chrysopoeic recipe. The encryption method is a variant of a Bellaso/Della Porta style-cipher, agreeing with the paper by Lang and Piorko. After correcting some errors in the seventeenth-century ciphertext and table it was noted that the cipherkey, 45 letters in length, forms part of the original plaintext and is also derived from an alchemical context. This article presents the transcription of the cipher table and ciphertext, the key, and the Latin plaintext, and discusses the decryption process as well as the historical context.
@inproceedings{lang2022solving, author = {Bean, Richard and Lang, Sarah and Piorko, Megan}, title = {Solving an alchemical cipher in a shared notebook of John and Arthur Dee}, booktitle = {Proceedings of the 5th International Conference on Historical Cryptology (HistoCrypt 2022)}, editor = {Dahlke, Carola and Megyesi, Beáta}, year = {2022}, series = {Linköping Electronic Conference Proceedings 188}, pages = {12--21}, doi = {https://doi.org/10.3384/ecp188388}, url = {https://ecp.ep.liu.se/index.php/histocrypt/article/view/388}, }

2021

Deciphering the Philosophers’ Stone: how we cracked a 400-year-old alchemical cipher

Richard Bean, Megan Piorko, and Sarah Lang

Oct 2021

Abs Bib

@online{cipher2021conversation,
  author = {Bean, Richard and Piorko, Megan and Lang, Sarah},
  title = {Deciphering the Philosophers' Stone: how we cracked a 400-year-old alchemical cipher},
  year = {2021},
  month = oct,
  day = {13},
  journal = {The Conversation},
  url = {https://theconversation.com/deciphering-the-philosophers-stone-how-we-cracked-a-400-year-old-alchemical-cipher-167900}
}

An alchemical cipher in a shared notebook of John and Arthur Dee [Work In Progress]

Sarah Lang and Megan Piorko

In Proceedings of the 4th International Conference on Historical Cryptology (HistoCrypt 2021), 2021

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Alchemy, while being known for its secrecy, cryptographical and stylistic devices, isn’t known for its ciphers in particular. However, ciphers can sometimes be found in alchemists’ and chymists’ (laboratory) notebooks. This paper discusses a ciphertext and cipher table found in a shared notebook by John and Arthur Dee (Sloane MS 1902). It presents a bibliographical description as well as context for interpretation. However, thus far it has not been possible to solve the cipher.
@inproceedings{LangPiorko2021, author = {Lang, Sarah and Piorko, Megan}, title = {An alchemical cipher in a shared notebook of John and Arthur Dee [Work In Progress]}, booktitle = {Proceedings of the 4th International Conference on Historical Cryptology (HistoCrypt 2021)}, editor = {Dahlke, Carola}, year = {2021}, series = {Linköping Electronic Conference Proceedings 183}, pages = {90--93}, doi = {https://doi.org/10.3384/ecp183161}, url = {https://ecp.ep.liu.se/index.php/histocrypt/article/view/161}, keywords = {alchemy, Arthur Dee, John Dee, cipher} }