Introduction
Cryptography, the art and science of secure communication, has a rich and intricate history dating back thousands of years. From ancient civilizations' rudimentary methods of secret communication to the sophisticated algorithms powering modern cryptographic systems, the journey of cryptography is both fascinating and indispensable in understanding the evolution of human civilization. This essay provides a general exploration of cryptography, tracing its origins, the formalization of cryptography as a field of study, and its pervasive influence on modern technology.
Origins of Cryptography
The origins of cryptography can be traced back to ancient civilizations, where the need for secure communication amidst conflicts, espionage, and trade necessitated the development of rudimentary cryptographic techniques. One of the earliest recorded instances of cryptography dates back to around 1900 BCE, with the use of hieroglyphic inscriptions on the tomb of Khnumhotep II in Egypt. These inscriptions were likely intended to conceal the secrets of the tomb's construction from unauthorized individuals.
Subsequent civilizations such as the Greeks and Romans made significant contributions to the field of cryptography. The Spartans, for instance, utilized a transposition cipher known as the Scytale, where a strip of parchment wrapped around a rod of a particular diameter was used to encode and decode messages. Meanwhile, the Romans employed substitution ciphers, such as the Caesar cipher, which involved shifting each letter in the alphabet by a fixed number of positions.
Formalization of Cryptography
The formalization of cryptography as a distinct field of study began to take shape during the Renaissance period, particularly with the emergence of polyalphabetic ciphers and the publication of seminal works on cryptography. One of the most notable figures in this regard is the polymath Leon Battista Alberti, who introduced the concept of polyalphabetic substitution in his treatise "Trattato della cifra" (Treatise on the Cipher).
In the 20th century, cryptography underwent a profound transformation, owing to advancements in mathematics, computing, and telecommunications. The pioneering work of figures like Claude Shannon, often regarded as the "father of modern cryptography," laid the theoretical groundwork for secure communication in the digital age. Shannon's seminal paper "Communication Theory of Secrecy Systems" published in 1949, established the principles of information theory and introduced the concept of perfect secrecy. Countless other individuals built off of his work and made advancements valuable to both times of war and of peace.
Modern Applications of Cryptography
In the contemporary era, cryptography permeates virtually every aspect of modern technology, serving as the cornerstone of cybersecurity, privacy protection, and digital authentication. The ubiquity of the internet and electronic communication has underscored the critical importance of cryptographic techniques in safeguarding sensitive information from unauthorized access and malicious attacks.
One of the most prevalent applications of cryptography is in the realm of secure communication protocols such as Transport Layer Security (TLS) and Secure Sockets Layer (SSL), which encrypt data transmitted over computer networks to ensure confidentiality and integrity. Cryptographic algorithms like the Advanced Encryption Standard (AES) and RSA (Rivest-Shamir-Adleman) are widely employed in securing data-at-rest and data-in-transit, ranging from online banking transactions to government communications.
More specifically, encryption of passwords is often undergone through "hashing and salting" algorithms. When a user creates a password with a website or company, the managing party runs the password through an algorithm that scrambles the password into mostly random letters, numbers, and symbols. This string of symbols is what the company stores; they never have to store the user's password itself. This protects the company from liability during data breaches, to a certain extent. When a user logs in with that site, the password they input is put through that same algorithm. If the resulting gibberish string matches the stored string, the user is given access to their account. The algorithm is such that no two strings will produce the same hash string, and it is infinitely difficult to reverse the hash to get the original string from the hashed string.
The advent of quantum computing poses both opportunities and challenges for the field of cryptography. Hashing algorithms are designed to be incredibly time-intensive for standard computers to break. While quantum computers hold the potential to break conventional cryptographic schemes by solving these infinitely difficult problems with incredible speed, they also open the door for the creation of even more complex security algorithms.
Conclusion
Modern day cryptography may look very different from the ciphers of the Egyptians, but the purpose is the same: putting a proverbial lock and key on information, making it accessible to the right people and inaccessible to the wrong ones. As our technology advances, so will our encoding and decoding capabilities.
Even with all of our fancy encryption, passwords still get broken. As a PSA: don't use the same password for every website.
See Also
Much of this material is sourced from Encyclopedia Britannica, 'Code Girls' by Liza Mundy, and my personal notes taken during a variety of Computer Science classes. Here are links to some of these sources, provided for optional further reading:
By Bailee Hodge