The English word cryptography comes from Greek.

"Cryptography" is composed of two Greek words: Κρυπτ? (kryptós) means "hidden, secret". Γρ?φειν (graphein) means "writing, recording". Put these two words together and you get cryptography. Its original meaning refers to some technologies used to encode and decode information. In traditional cryptography, encryption and decryption mainly use basic techniques such as simple substitution or shift. "Cryptography" implies the overall complexity and difficulty of cryptography.

As a science, cryptography has a long history. As early as thousands of years ago, ancient civilizations began to use various encryption technologies to protect military intelligence and sensitive information. During the Greek and Roman periods, some ancient scholars had already studied some basic encryption and decryption methods. For example, Aristotle, Julius Cesar of Universal Rome, etc. all made contributions to cryptography.

Medieval Arab scholars also conducted in-depth research in cryptography and developed many new cryptography technologies. Among them, well-known Arab mathematicians Al-Kindi, Ibn al-Durayhim and Abu Rayhan al-Biruni are all very important contributors.

In modern times, cryptography is widely used in many fields. Many banks and financial institutions use cryptography to protect customer privacy and financial data and to ensure network and electronic communications security. Government and military agencies use cryptography to protect sensitive information and military intelligence. There are also many commercial companies that use cryptography to prevent cyber attacks and hackers. With the development of the Internet and mobile communications, the application scope of cryptography has become more extensive, and its importance to network and information security has become increasingly significant.

The word "cryptography" comes from Greek, which reflects the essential characteristics and complexity of cryptography. This subject has a very long history. Through the development and evolution of various encryption methods, the theory and application of cryptography have become very mature.

Modern cryptography

Modern cryptography not only provides more secure, reliable and efficient encryption methods, but also involves digital signatures, authentication, public key infrastructure, cryptographic protocols, etc. Multiple areas. The research on cryptography pays more and more attention to information security and network security, and it has become an important part of disciplines such as computer science, information engineering, and communications. Some emerging technologies and applications, such as blockchain, quantum cryptography, etc., are also gradually involving the application of cryptography.