Cryptography or cryptography is the science of writing codes and secure communication codes, and it is one of the most important elements involved in the blockchain industry and modern digital currencies. The encryption techniques used today are the result of a very long history of development. Since ancient times, people have used cryptography to transfer information in a secure manner. Below is the fascinating history of cryptography that led to the advanced and sophisticated methods used in modern digital encryption.

The ancient roots of cryptography

Primitive cryptographic techniques are known to have existed in ancient times and most early civilizations appear to have used cryptography to some extent such as code substitution which is the basic form of cryptography in both ancient Egyptian and Mesopotamian writings. The oldest known example of this type of cryptography was found in the tomb of an Egyptian nobleman named Khnumhotep II who lived about 3,900 years ago.

The purpose of the symbol replacement in the Khnumhotep II inscription was not to hide information but to enhance its linguistic appeal. The oldest known example of cryptography used to protect sensitive information occurred about 3,500 years ago when a Mesopotamian scribe used cryptography to hide a pottery glaze formula that was used on clay tablets.

In later periods of antiquity cryptography was widely used to protect important military information, a purpose it still serves to this day. In the city of Sparta in Greece, messages were encrypted by writing them on parchment over a cylinder of a certain size, making the message indecipherable until it was wrapped around a similar cylinder by the recipient. Likewise, spies in ancient India are known to have used encrypted messages as early as the 2nd century BC.

Perhaps the most advanced cryptography was used in the ancient world by the Romans. A notable example of Roman cipher known as Caesar's cipher involves transforming letters for an encrypted message a certain number of places down the Latin alphabet. Knowing this system and the number of places to change letters, the recipient can decode the message, and if he fails, the message will no longer be readable or understandable.

Developments in the Middle Ages and the Renaissance

During the Middle Ages, cryptography became increasingly important, but the substitution cipher, of which Caesar's method is an example, remained the standard in cryptography.

The science of cryptanalysis, which is the science through which codes are broken and solved, has begun to catch up with the primitive sciences that are still relatively primitive in cryptography. Al-Kindi, a well-known Arab mathematician, developed a technique known as frequency analysis around 800 AD that made the substitution code vulnerable to decryption. For the first time people trying to decipher encrypted messages had access to a systematic way to do so, making it necessary for cryptography to advance further in order to remain useful.

In 1465, Leon Alberti developed a polyalphabetic cipher which was considered a solution against the technique of frequency analysis. In a polyalphabetic cipher a message is encoded using two distinct alphabets. The first is the alphabet in which the original message is written while the second is a completely different alphabet in which the message appears after it is encrypted. Combined with traditional substitution ciphers, ciphers have greatly increased the security of encrypted information. Unless the reader knows the alphabet in which the letter was originally written, Kennedy's frequency analysis method is of no use.

New methods of encoding information were also developed in the Renaissance period, including a popular early method of binary encoding invented by the famous scientist Sir Francis Bacon in 1623.

More progress in recent centuries

Cryptography has continued to advance gradually over the centuries. In the 1870s Thomas Jefferson described a major event in cryptography although it was probably never built. His invention known as the Cipher Wheel consisted of 36 rings of letters on moving wheels that could be used to achieve complex encryption. This concept was so advanced that it served as the basis for US military encryption until as late as World War II.

World War II also saw the perfect example of analog cryptography known as the Enigma machine. Like the wheel cipher, this device used by the axis powers used rotating wheels to encode the message, making it practically impossible to read without another puzzle. But eventually early computer technology was used to help break the Enigma code, and successful decoding of Enigma messages is still considered an element. Crucial to the eventual Allied victory.

Cryptography in the computer age

With the spread of computers, encryption has become much more advanced than it was in the analog era. 128-bit mathematical encryption is much stronger than any ancient or medieval encryption and is now the standard for many sensitive devices and computer systems. Beginning in 1990, computer scientists were developing an entirely new form of cryptography, called quantum cryptography, that hoped to once again raise the level of protection afforded by modern cryptography.

Recently, encryption techniques have also been used to make the creation of digital currencies possible, as digital currencies take advantage of advanced encryption techniques, including hash functions, public key encryption, and digital signatures. These technologies are primarily used to ensure the security of data stored on the blockchain and to authenticate transactions. A specialized form of cryptography known as the Elliptical Curve Digital Signature Algorithm (ECDSA) underpins Bitcoin and other cryptosystems as a way to provide additional security and ensure that funds can only be used by their rightful owners.

Cryptography has come a long way in the past 4,000 years and is not likely to stop advancing anytime soon. As long as sensitive data requires protection, encryption will continue to advance. Although the cryptographic systems used in blockchain today represent some of the most advanced forms of this science, they are also part of a tradition that extends throughout much of human history.