encryption-history Archives - theindicscholar.com

Introduction

A code can be defined as a set of words, figures, letters, numbers, or symbols generally used to represent a secret message that needs to be conveyed to a specific group of people across a certain distance or time period. The earliest examples of codes can be traced to prehistoric times when our ancestors used sign language to convey messages. In fact, the language that we use regularly or the numerals that we use to do calculations are also codes or patterns recognized only by a certain kind of animal, that is, Homo sapiens or modern human beings. In this blog, we discuss the evolution of codes along with humans across civilizations. We discuss how codes and encryption helped direct human society for nearly 3000 years across cultures, nations, and continents.

1. The Mesopotamian Tablet (~1500 BCE)

The Mesopotamians were the first to use some form of codes in known history. They used clay tablets to encrypt codes in cuneiform script. A classic example is that of the clay tablet found from around 1500 BCE. It contains a cryptographic formula for making pottery glaze. The encryption was not an accident; the scribes deliberately altered some signs to preserve knowledge from foreign or unworthy people. It is considered the oldest surviving record of codes.

2. The Egyptian Hieroglyphic Cipher (~1500 BCE)

Hieroglyphs were the ancient Egyptian writing system from 2500 BCE. The Egyptians combined idiographic, iconographic, syllabic, and alphabetic elements to write religious and political texts on papyrus and wood. In some Hieroglyphic texts found in the tombs of the Pharaohs from the second millennium BCE, it has been seen that the Scribes and Priests used unusual or rare Hieroglyphics to alter or distort the true meaning in order to create a mythical aura. The texts were used to preserve rituals for funerary and other religious purposes that were limited only to the scribes and royals.

3. The Hebrew Atbash Cipher (~600 BCE)

The Atbash is a monalphabetic substitutional cipher originally used in the Hebrew alphabet. There, the series was reversed so that the first letter became the last letter, and the second letter became the second to last cipher, and so on.

Original

Cipher

The name itself is derived from the first, last, second, and second-to-last Hebrew alphabet- Aleph, Taw, Bet, and Shin. Several verses of the Bible, as described by the commentators as being an Atbash, like in the book of Jeremiah, names like Sheshach and Lev-Kamai are written as Atbash for the Hebrew words for Babylon and Chaldeans. It is important because a simple substitution cipher was used in the Bible to hide sensitive references.

4. The Spartan Scytale (~400 BCE)

The Ancient Greeks, especially the Spartans, used a tool called a Scytale, where a leather strip was wound around a cylinder, with hidden messages written on the strip. Suppose the cylinder allows writing four letters around in a circle, and five letters downwards. And the message to be sent is “ The soldiers are coming”. It can be written on the strip as

	T	H	E	S	O	The End of The Strip
The Start of The Strip	L	D	I	E	R
	S	A	R	E	C
	O	M	I	N	G

Thus, when the strip is unwound, it will read as TLSOHDAMEIRISEENORCG, thus concealing the message if the process is not known.

5. Kautilya’s Arthashastra (~300 BCE)

The Indian political genius and the teacher of Emperor Chandragupta Maurya, Vishnugupta Chanakya, also known as Kautilya, in his text on statecraft, “ Arthashastra,” states the art of understanding codes and ciphers as Mlecchita Vikalpa (secret writing). In this form of code, the short and long vowels, the anusvara, and the spirants are interchanged with consonants and the conjunct consonants. They are given in the first and second row in the table below without interchanging.

ṛ

ṝ

ḷ

ḹ

ṃ

ḥ

ṣ

ṅ

ṭh

ḍ

ḍh

ṇ

The Arthashastra is one of the earliest written manuals of statecraft and espionage, and perhaps the earliest manual of the use of cryptography mentioned for spy operations in the world.

6. Caesar Cipher (~58 BCE)

The Caesar Cipher, or the Shift Cipher, is one of the most popular encryption techniques named after the great Roman General, Gaius Julius Caesar. It is a type of encryption in which each letter is substituted by another letter of some fixed number of positions down the alphabet. For eg:-if the letters are shifted by a position of 3, A becomes D, B becomes E, and so on. This Cipher is one of the simplest and most widely used ciphers even today.

7. Al-Kindi’s Cryptoanalysis (~950 CE)

Abu Yusuf Yaqub ibn Ishaq as-Sabbah al-Kindi was an Arab muslim polymath from Baghdad, active as a mathematician, philosopher, physician, and music theorist. Apart from his contribution in the above-mentioned fields, he was also a pioneer of cryptography. He is credited with developing a method whereby observing the variations in the frequency of the occurrence of letters, ciphers could be analyzed and decoded. In his book, Risala fi Istikhraj al-Kutub al-Mu’ammah (On Extracting Obscure Correspondence), he gave this idea of frequency analysis as an important tool for cryptoanalysis.

8. Alberti Cipher Disk (~1467 CE)

The Alberti cipher was created by the Italian architect Jean Battista Alberti around 1467 CE. He constructed a device called Formula, which became the first example of polyalphabetic substitution with mixed alphabets and variable periods. The device consisted of two concentric disks attached to a common pin, and could rotate one disk with respect to another. The outer one, called Stabilis, consisted of uppercase letters for plaintext, and the inner one, called Mobilis, consisted of lowercase letters mixed for cyphertext. The circumferences of both the disks were divided into 24 equal parts. The outer disk also contained numbers from 1 to 4. His device revolutionized encryption, as compared to previous versions, his was very complex and impossible to break without knowledge of the device. It is also considered the birth of modern ciphers.

9. Vigenere Cipher (~1550 CE)

The Vigenere Cipher is a method of encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar Cipher, whose increment is determined by the corresponding letter of another text, known as the key. Suppose the plaintext is “welcome to the blog”, and the key is “hwdnjpweojkdpyjf”. So the first letter “w” becomes “d” because “w” is shifted by 7 positions, as “h” is the eighth letter of the alphabet, and starting from 0, the right number is 7, so “w” becomes “d”. Similarly, the second letter “e” becomes “a”, the third letter “l” becomes “o”, and so on. So the plaintext “welcome to the blog” becomes “daopxba xc crh qnwl”. This type of encryption was first described by Giovan Battista Bellaso around the 1550s and popularised in the 1560s by Friedrich Kasiski. The scheme was misattributed to Blaise de Vigenere in the 19th century and so acquired its present name.

10. Mughal/ Ottoman Court Codices (~16th – 17th century)

The courts of the Mughal and the Ottoman Empire used codes in a unique way. The Mughals used Persian-style cyphers in secret poems named “rekhta”. Emperor Akbar and the later emperors had scribes trained in ramz-nigari (“secret writing”). The Ottomans used numbers in ciphers. The scribes kept codebooks to decipher secret messages sent embedded with numbers. Both the empires used cryptography as an essential tool learned by their scribes to store and send messages through poetry and numbers.

11. Playfair Cipher (~1854 CE)

The Playfair Cipher, or Playfair Square, or Wheatstone-Playfair Cipher, is the first diagram substitution cipher. It was invented in 1854 by Charles Wheatstone, an English physicist, and promoted by Lord Playfair, an English scientist and politician. It was the first cipher to encrypt pairs of letters in cryptographic history. It was used in telegraphs by the British in the First World War.

12. The Zimmerman Telegram (~1917 CE)

The Zimmerman telegram was a secret diplomatic communication between the German Empire and Mexico during the First World War. The German Empire promised support to Mexico to reclaim Texas, Arizona, and New Mexico from the USA. The telegram was intercepted by the British intelligence, which ultimately led to the participation of the USA in World War I.

13. One Time Pad (OTP) (~1920-present)

The One-Time Pad (OTP) is an encryption technique that cannot be deciphered. It requires the use of a single-use pre-shared key that should be larger than or equal to the actual message. In this type of encryption, the plaintext is encrypted by combining with the corresponding bit or character from the pad using modular addition. The ciphertext cannot be decoded as long as the key is larger than the actual plaintext, and is totally random, never reused, and never shared with any third party. It is the mathematically unbreakable, even today, if used correctly.

14. The Enigma Machine (~1920-50)

The Enigma Machine was a cipher device developed and used in the 1930s and 40s extensively by the Nazi Party. The machine had an electromechanical rotor system that scrambled the 26 letters of the alphabet. In this machine, one person entered texts from the keyboard and the other person wrote down the corresponding illuminated lights. These illuminated letters acted as the cipher text. During the Second World War, Nazi Germany sent messages through the Enigma machine, which was ultimately cracked by the British scientist Alan Turing and his team.

15. RSA Public-Key Cryptography (1977)

The Rivest-Shamir-Adleman (RSA) cryptography is a public key system used for secure data transmission. Named after the cryptographers- Ron Rivest, Adi Shamir, and Leonard Adleman, this is the foundation of modern internet security, from ATMs to WhatsApp. The system uses large prime numbers for the key generation used in encryption/decryption. Suppose Mr. A wants to send a message or receive a message from Mr. B, in the RSA system, Mr. A must use Mr. B’s public key to encrypt his messages or verify messages from Mr. B, and the same goes for Mr. B.

16. Quantum Cryptography (1984-present)

It is the science of using Quantum mechanical properties like Quantum Entanglement and the no-cloning theorem in cryptography. The most famous application is Quantum Key Distribution (QKD), which allows two parties to share a secret key with guaranteed security. If anyone tries to interfere, the act of measuring quantum particles will destroy them, revealing the spy. This makes quantum cryptography virtually impossible to break by classical computers and even resistant to quantum computers. Countries like China, the USA, and India are experimenting with satellite-based QKD to secure national and governmental information.

Reflection and Conclusion

From Mesopotamian Clay Tablets to QKD, codes and cryptography have evolved uniquely. Each code has its own story- sometimes sending important secret information, sometimes preserving valuable information. Codes have always been used both offensively and defensively. The journey of cryptography shows that while the process evolves, the destination always remains the same. Hope you all liked this blog. Thanks for reading it. Please like and share if you find this blog useful.

Tag: encryption-history

A History of Secret Codes: From Mesopotamian Tablets to Modern Encryption