Cryptography, the science of writing codes and ciphers for secure communication, is one of the most important elements in the creation of cryptocurrencies and modern blockchains. The cryptographic techniques used today, however, are the result of a long history of development. Since ancient times, people have used encryption to transmit information securely. The following is the fascinating history of cryptography, which resulted in the advanced and sophisticated methods used in modern digital cryptography.
The Ancient Roots of Cryptography
We know that primitive encryption techniques existed in ancient times, and most ancient civilizations appear to have used some level of encryption. Symbol substitution - the most basic form of cryptography - appears in both ancient Egyptian and Mesopotamian writings. The oldest known example of this type of encryption was found in the tomb of an Egyptian nobleman named Khnumhotep II, who lived approximately 3,900 years ago.
The purpose of replacing symbols in Knhumhotep's inscription was not to hide information, but rather to improve its linguistic appeal. The earliest known example of cryptography being used to protect sensitive information occurred around 3,500 years ago, when a Mesopotamian scribe employed cryptography to hide a formula for ceramic glaze, used on clay tablets.
After antiquity, encryption was widely used to protect important military information, a purpose it still serves today. In the Greek city-state of Sparta, messages were encrypted, being written on parchment placed on a cylinder of a specific size. The message was only deciphered when placed inside a cylinder of similar size by the recipient. Similarly, spies in ancient India are known to have used coded messages as early as the second century BC.
Perhaps the most advanced encryption in the ancient world was developed by the Romans. A prominent example of Roman cryptography, the Caesar cipher, involved replacing the letters of a message with other letters that were a few positions lower in the sequence of the Latin alphabet. Knowing this system and the number of positions to be moved, the recipient could decode the unreadable message.
Developments in the Middle Ages and Renaissance
Throughout the Middle Ages, cryptography became increasingly important, but substitution ciphers, of which the Caesar cipher is an example, remained the standard. Cryptanalysis, the science responsible for breaking codes and ciphers, began to catch up with the still relatively recent science of cryptography. Al-Kindi, a famous Arab mathematician, developed around 800 AD a technique known as frequency analysis, which made substitution ciphers vulnerable to decoding. For the first time, people trying to decipher encrypted messages had access to a systematic method for doing so, making it necessary for encryption to advance even further to remain useful.
In 1465, Leone Alberti developed the polyalphabetic cipher, which is considered the solution against Al-Kindi's frequency analysis technique. In a polyalphabetic cipher, a message is encoded using two distinct alphabets. One is the alphabet in which the original message is written, while the second is an entirely different alphabet in which the message appears after being encoded. Combined with traditional substitution ciphers, polyalphabetic ciphers have greatly increased the security of encoded information. Unless a reader knew the alphabet in which the message was originally written, the frequency analysis technique would be of no use.
New methods of encoding information were also developed in the Renaissance period, including a popular ancient method of binary encoding developed in 1623 by the famous philosopher and scientist Sir Francis Bacon.
Advances in More Recent Centuries
The science of cryptography has continued to advance progressively over the centuries. A major advance in cryptography was described, though perhaps never built, by Thomas Jefferson in the 1790s. His invention, known as the cipher wheel, consisted of 36 rings of letters on movable wheels that could be used to obtain a cipher. complex. This concept was so advanced that it served as the basis for American military encryption until World War II.
World War II also saw the perfect example of analog cryptography, known as the Enigma machine. Similar to the cipher wheel, this device, employed by the Axis Powers, used rotating rings to encode a message, making it practically impossible to read the message without another Enigma machine. Computer technology was eventually used to help break the Enigma cipher, and the successful decoding of Enigma messages is still considered a critical element of the Allies' eventual victory.
Cryptography in the Computing Age
With the rise of computers, cryptography has become much more advanced than in the analog era. 128-bit mathematical encryption, much stronger than any ancient or medieval cipher, is now the standard for many sensitive devices and computing systems. Beginning in 1990, an entirely new form of cryptography, dubbed quantum cryptography, was under development by computer scientists, who sought to once again raise the level of protection offered by modern cryptography.
More recently, cryptographic techniques have also been used to make cryptocurrencies possible. Cryptocurrencies leverage several advanced cryptographic techniques, including hash functions, public key cryptography, and digital signatures. These techniques are mainly used to ensure the security of data stored on blockchains and to authenticate transactions. A specialized form of cryptography, known as the Elliptic Curve Digital Signature Algorithm (ECDSA), underpins Bitcoin and other cryptocurrency systems as a means of providing extra security and ensuring that funds can only be used by their rightful owners.
Cryptography has come a long way in the last 4,000 years, and it probably isn't stopping anytime soon. As long as sensitive data requires protection, encryption will continue to advance. Although the cryptographic systems used in cryptocurrency blockchains today represent some of the most advanced forms of this science, they are also part of a tradition that has spanned much of human history.
