Saying to not say

All languages are codes. And all codes are at once bridges and walls, barriers and passageways. In essence, they function as border checkpoints.  In some languages, the term for border checkpoint or customs comes from the Arabic word diwan, meaning office or register. But it also means couch, symbolizing the power of those who sat in such offices and guarded that register, allowing or forbidding passage and setting the requirements. All codes are interfaces. And interfaces, like all customs, are only apparently neutral.

Abū Yūsuf Yaʿqūb ibn Isḥāq ibn al-Ṣabbāḥ ibn ʿUmrān ibn Ismāʿīl al-Kindī (in arabic أبو يوسف يعقوب ابن اسحاق ابن الصّبّاح ابن عمران ابن اسماعيل الكندي‎) was born at the beginning of the ninth century, in Kufa, in present-day Iraq. His name is like a convoy, almost like a genetic code spelling out countries, ancestors, class of origin, and honorary titles for those who know how to decode it. Naming is never neutral, either. Names are our first interface with our world.

Al-Kindi — as he is usually called for simplicity’s sake — came from an aristocratic family that originated in what is now Yemen. He was a multifaceted scholar, skilled in music, science, astronomy, astrology, philosophy, mathematics, metaphysics, physics, and pharmacology. He studied in Baghdad, near his hometown, at Bayt al-Ḥikma, the House of Wisdom. About half a million volumes were collected here in perfect order: the most extensive library in the Arab-Islamic world, including works in Arabic, Greek, Syriac, Hebrew, Coptic, Persian, and Sanskrit.  Surrounded by these texts, Abū Jaʿfar Muḥammad ibn Mūsā al-Khwārizmī, known simply as al-Khwārizmī, also studied in the same building during the same period. He is considered the father of algebra, and the term “algorithm” comes from his name. The House of Wisdom was the pride of the Abbasid Caliphate. It was the hub of what would later be called the Islamic Golden Age, a long period from the mid-eighth century to 1258.

At the House of Wisdom, the young al-Kindi soon learned ancient Greek. He was among the very first, perhaps the first, to translate Aristotle’s writings into Arabic. The preservation of the Greek philosophical tradition during that era was largely due to Arab scholars: al-Kindi, indeed, then Avicenna, more than a century later, and again Averroes a century after that. We often tend to forget this on our side of the Mediterranean (but perhaps that happens also on the other side).

To translate, from the Latin trans ducere, means to lead through, to cross a border or customs, to recode from one code to another. As in trading, something is lost, something is gained. Such a passage is never neutral. For some crossings, such as linguistic translations, all it takes — and this is no small thing — is a profound knowledge of both languages and the worlds surrounding them. But there are even more complicated crossings: those involving closed-off, sealed customs, passable only by presenting false documents, wearing disguises, hiding (encrypting, from the Greek kryptós) the messages one carries, changing one’s features, their face, their facies (Latin for appearance) at the interface, to safeguard the integrity of what is passing through.

Al-Kindi was also considered one of the best calligraphers of this time: his lettering was elegant, harmonious, and easy to read. Today, he is recognized as the father of cryptanalysis, the techniques and methods used to decypher encrypted messages. Al-Kindi’s method, known as “frequency analysis,” was a stroke of genius, only fully appreciated in hindsight. Essentially, it involves studying the frequency with which characters recur in an encrypted text. In any language, the frequency of each character’s use is rather consistent. Therefore, breaking the code becomes, all things considered, a straightforward task by matching the code character with the one in the source language to reveal the message hidden behind its mask. “Rather,” and “all things considered”. It’s a matter of statistics and probability, like making a compass capable of pointing toward the truth, an insight that was centuries ahead of its time. This frequency analysis method, developed and adapted, formed the basis of cryptanalysis until at least the twentieth century. Then came the world wars, where making and breaking codes became a matter of victory or defeat, life or death. With the advent of electronic computers, computer science has advanced cryptanalysis to the present day.

Cryptanalysis and cryptography are two sides of the same coin. Like day and night. Cryptanalysis constantly strives to shed light on what cryptography strives to obscure. Cryptography veils, cryptanalysis reveals. For centuries, they have chased each other in an increasingly complex, refined, and accelerated game of cops and robbers. Today, however, the balance seems broken. The chase is over. Cryptography has won. In 2023, a team of researchers at the University of York sent a message 224 km away over an undersea fiber-optic network. The communication was protected by a “quantum” encryption system, indecipherable by any external cryptanalysis system, and impenetrable in both practice and theory. Perhaps good news. Maybe not. Cryptanalysis and cryptography are two sides of the same coin. Like power and counter-power. If the balance is lost, we risk being entirely in the hands of those who hold the coin. 

Encryption systems protect everything we send through messaging apps: emails, online business meetings, and banking transactions. Our sensitive data, our indelible footsteps in the digital world, and our memories (and one could almost say our identity) are now protected and kept safe by encryption. Al-Kindi died in misfortune and loneliness between 866 and 873. Sources (interfaces between past and present) do not agree on the reasons for his downfall: political issues and power plays, it seems. Before his death, his personal library was confiscated. After his death, his works were almost completely forgotten. Four centuries later, in 1258, Hulagu Khan, a grandson of Genghis Khan, entered Baghdad at the head of a massive and ruthless Mongol army and burned the city to the ground. The few survivors recounted that horror; they wrote that the waters of the Tigris River had turned black from the ink of the tens of thousands of volumes of the Bayt al-Ḥikmah, the House of Wisdom, that had been thrown into its bed. Further west, the devastation had already come with the weapons and insignia of European crusaders.

According to tradition, al-Hasan, the grandson of Muhammad, said, “On the Resurrection Day, the ink of the scholars will be weighed out against the blood of the martyrs. Then, the ink of the scholars will outweigh the blood of the martyrs.” This maxim inspired the Abbasid Caliphate, the promoter and main financier of the splendor of the Islamic Golden Age. In Kufa, al-Kindi’s hometown, stands one of the oldest mosques in the world, completed in 670, only 40 years after the death of Muhammad. It has four minarets and is accessed through five gates. According to ancient Shiite tradition, it was from here that the universal flood was unleashed, growing wider and wider until it submerged the whole world. And again, from here, thanks to God, the waters began to recede, to be reabsorbed by the earth.  Everything is the opposite of everything else. And vice versa.