In a testament to how difficult it is to break good encryption, it took five centuries for the secret code used by Spanish King Ferdinand to be cracked.
The intricate code that was comprised of over 200 unique characters that Ferdinand II of Aragon relied on to confidentially communicate with his military commanders has baffled experts for centuries.
Advertisement - story continues below
Spain’s intelligence services have announced a breakthrough that allowed for the mysterious encryption to be cracked. The news was hailed by researchers and historians alike who hope to glean insight into the mind of the man instrumental in the Reconquista.
500-year-old Spain secret letter code cracked https://t.co/Pvc10mWtzX
— BBC News (World) (@BBCWorld) February 3, 2018
Ferdinand of Aragon’s letters have tantalised historians for centuries.
Constructed using more than 200 special characters, they were deciphered by the country’s intelligence agency.
He was behind the final recapture – Reconquista – of Spain from the Moors in 1492 and Columbus’s journeys to the Americas.
The letters between Ferdinand and Gonzalo de Córdoba include instructions on strategy during military campaigns in Italy in the early 16th Century. They were written using secret code in case they fell into enemy hands.
The letters are on display at Spain’s Army Museum in Toledo and it took intelligence services almost half a year to decipher four of them, some of which went on for over 20 pages.
The code-cracking has been described by some as a “Rosetta Stone” moment, amid hopes that it could lead to more coded letters being deciphered.
Details outlined in the letters range from instructions on troop deployments to admonishing the commander for not consulting the king before launching diplomatic initiatives.
In the early 16th Century, it would have taken 15 days for the letters to get between the monarch’s residences to south-eastern Italy where the commander was based.
What the code looked like
The mysterious coding system used by Ferdinand of Aragon and Gonzalo de Córdoba was highly complex. It was constructed using 88 different symbols and 237 combined letters.
For each letter there were between two and six figurative characters such as triangles or numbers.
To complicate matters even further, the symbols used in the letters were written without separating words and phrases.
Advertisement - story continues below
Mystery of 500-year-old secret code used by Spanish king finally solved https://t.co/fB9WFNiHT9
— The Independent (@Independent) February 4, 2018
Additional details via the UK Independent:
No one had been able to decipher the letters for centuries, as the substitution table the king used to create the code had not been preserved.
However, when the Army Museum in Toledo displayed the letters in 2015, experts from the Spanish National Intelligence Center (CNI) were asked for help to crack the code.
The museum provided the CNI with two letters written in 1502 and 1506.
At the foot of one letter de Córdoba, known as “The Great Captain”, had deciphered a few sentences, allowing the experts an insight into the code.
Within the letters the CNI specialists found orders, threats and instructions for military engagements.
The discovery was described by Spanish national daily newspaper ABC as “one of the great mysteries in the history of Spain”.
In total, 88 different symbols and 237 “combined letters” were used to create the ”Great Captain code”.
The breaking of the encryption will be of great importance to those seeking to get a better understanding of this near-mythic figure whose reign was during a period of great historic significance.
Facebook has greatly reduced the distribution of our stories in our readers' newsfeeds and is instead promoting mainstream media sources. When you share to your friends, however, you greatly help distribute our content. Please take a moment and consider sharing this article with your friends and family. Thank you.