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How Looking for Ciphers in Shakespeare Shaped Modern Codebreaking

Detail of "Giambattista della Porta," De furtivis literarum notis (1591) (courtesy Folger Shakespeare Library)
Giambattista della Porta, “De furtivis literarum notis” (1591) (courtesy Folger Shakespeare Library)

The theory that statesman and scientist Francis Bacon was the ghostwriter behind Shakespeare, and embedded the Bard’s plays with ciphers, had a major influence on modern cryptography. That obscure story is at the heart of Decoding the Renaissance: 500 Years of Codes and Ciphers, which opened this week at the Folger Shakespeare Library in Washington, DC.

William F. Friedman and Elizebeth S. Friedman (1957) (photograph by Walter Bennett)
William F. Friedman & Elizebeth S. Friedman (1957) (photograph by Walter Bennett)

Codebreaking duo William and Elizebeth Friedman got their start working on a theory sponsored by a wealthy textile magnate that Bacon secretly penned the Shakespeare plays. As it became clear this wasn’t the case, they moved onto other cipher work, namely for the US government. From the 1920s to 50s, Friedman, often collaborating with his wife, was the country’s leading cryptoanalyst. His greatest victory was arguably in 1940 when the US Army Signals Intelligence Service led by Friedman broke the “Purple” cipher used by Japan — a feat many had considered impossible.

The Friedmans’ story is central to Decoding the Renaissance. Curated by Bill Sherman, head of research at the Victoria & Albert Museum, the exhibition brings together notable texts from the Folger Library, Library of Congress, and other institutions. There’s also a rare guest: the Voynich Manuscript (which Friedman also obsessed over). As the Washington Post reported, it’s the first time the manuscript written in a mysterious language has been loaned by Yale University since it arrived at the Beinecke Library in 1969. Alongside are objects like the first cryptography book: the 1518 Polygraphiae libri sex by Johannes Trithemius. Others demonstrate how ideas like invisible ink have centuries of history; for example, the 1708 Mercury; or the secret and swift messenger by John Wilkins suggests writing with “juice of glow-worms,” visible just in the dark.

Why Bacon got wrapped up into Shakespeare and later contemporary military codes goes back to his idea for the biliteral cipher. The cipher used a two-letter system of A’s and B’s in five letter combinations, but any two things could be substituted, so it’s possible to embed it almost anywhere. As Friedman put it, “signify omnia per omnia (anything by means of anything),” an idea he illustrated in a 1916 drawing of a flower. In another example, Friedman staged a military officers photo where by the A’s looking at the camera and B’s looking away, they spell out Bacon’s axiom “knowledge is power” (which Friedman had carved on his and Elizebeth’s grave). You can see the photograph discussed by curator Bill Sherman in this video, with more images from Decoding the Renaissance below.

William F. Friedman," Cipher Baconis Gallup" (March 1916) (courtesy of the Bacon cipher collection, Manuscripts and Archives Division, The New York Public Library, Astor, Lenox and Tilden Foundations)
William F. Friedman,” Cipher Baconis Gallup” (March 1916) (courtesy of the Bacon cipher collection, Manuscripts and Archives Division, The New York Public Library, Astor, Lenox and Tilden Foundations)
Samuel Morland, "A new method of cryptography," London (1666) (courtesy Folger Shakespeare Library)
Samuel Morland, “A new method of cryptography,” London (1666) (courtesy Folger Shakespeare Library)
Johannes Trithemius, "Polygraphie et universelle escriture caballistique" (1625) (courtesy Folger Shakespeare Library)
Johannes Trithemius, “Polygraphie et universelle escriture caballistique” (1625) (courtesy Folger Shakespeare Library)
Giambattista della Porta, "De furtivis literarum notis" (1591) (courtesy Folger Shakespeare Library)
Giambattista della Porta, “De furtivis literarum notis” (1591) (courtesy Folger Shakespeare Library)
The Voynich Manuscript. Cipher manuscript, ca. 1410–30. Courtesy of the Beinicke Library, Yale University.
“The Voynich Manuscript” (1410–30) (courtesy of the Beinicke Library, Yale University)
The Voynich Manuscript. Cipher manuscript, ca. 1410–30. Courtesy of the Beinicke Library, Yale University.
“The Voynich Manuscript” (1410–30) (courtesy of the Beinicke Library, Yale University)

Decoding the Renaissance: 500 Years of Codes and Ciphers is at Folger Shakespeare Library (201 East Capitol Street, SE, Washington, DC) through February 26. 

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