Philip the Second´s Cifra General
On May 24th, 1556, barely one year into power,
Spanish Emperor Philip the Second wrote a letter to his uncle Ferdinand Ist (Emperor
of the German Empire and King of Hungary) his decision to change his father
Charles Vth´s ciphers, as they fell into obsolescence or were compromised.
Six months later, the first Cifra General (General Cipher) of Philip the
Second´s kingdom was in use.
The Cifra General was used for communications
between the Emperor and his main government members abroad. We can see it
as a diplomatic master cipher. The Cifra General of 1556 was
addressed to:
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the Princess of Portugal
-
the Duke of Saboya, governor of Flanders
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the Viceroys of Naples, Sicily and Catalonia
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the Cardinal of Trento
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the Marquis of Pescara at Milan
-
the Cardinal of Burgos at Sena (¿Siena?)
-
Prince Andrea Doria
-
ambassadors in Rome, Venice, Genoa, France and
England.
The Cifra General of 1556 is dated at Gent on
November 8th, 1556 and, according to David Kahn, it was one of the finest
encryption systems in its time. It is made up of three parts: a
monoalphabetic (with homophones) substitution vocabulary, a list of digraphs and
trigraphs, and a dictionary of common terms.
The original Cifra General is stored at the Simancas
Archive, Spain. This copy comes from the book by J.P. Devos (Les
chiffres de Philippe II (1555-1598) et du Despacho Universal durant le XVIIe
Siecle, 1950).
Alphabet
Digraph/trigraph table Duplices (double letters)
Dictionary
Appendix: The Cifra General under attack
Philip the Second´s Cifra General kept secrets safe
for barely three months. In February 1557, the Papal Secretary Triphon
Bencio managed to break the cipher of a letter sent to the Cardinal of Burgos,
Francisco Pacecco, at Siena; Pacecco was one of the recipients of the Cifra
General. From there, the cryptanalist reconstructed part of the cipher.
Here´s the fragment he could find out. The original was published in the
book of Aloys Meister Die Geheimschrift im Dienste der Päpstlichen Kurie von
ihren Anfängen bis zum Ende des XVI. Jahrhunderts (Encrypted writihg at the
Papal Curia from its beginnings to the end of the XVIth Century).
© Arturo Quirantes Sierra. Some rights reserved, according to Creative Commons License
