How a 400-year-old alchemical cipher was cracked

[Paul Ferguson]

"The setting was Amsterdam, 2019. A conference organised by the Society for the History of Alchemy and Chemistry had just concluded at the Embassy of the Free Mind, in a lecture hall opened by historical-fiction author Dan Brown. At the conference, Science History Institute Postdoctoral Researcher Megan Piorko presented a curious manuscript belonging to English alchemists John Dee (1527–1608) and his son Arthur Dee (1579–1651). In the pre-modern world, alchemy was a means to understand nature through ancient secret knowledge and chemical experiment. Within Dee’s alchemical manuscript was a cipher table, followed by encrypted ciphertext under the heading “Hermeticae Philosophiae medulla” — or Marrow of the Hermetic Philosophy. The table would end up being a valuable tool in decrypting the cipher, but could only be interpreted correctly once the hidden “key” was found. It was during post-conference drinks in a dimly lit bar that Megan decided to investigate the mysterious alchemical cipher — with the help of her colleague, University of Graz Postdoctoral Researcher Sarah Lang."

https://www.thetimes.com.au/world/10819-...cal-cipher