What belongs to classical ciphers

Caesar ciphers, Virginia ciphers, and substitution ciphers belong to classical ciphers.

A classical cipher is a cryptographic system that uses operations such as simple substitutions and shifts for traditional encryption. It primarily uses fixed encryption methods for encryption, often based on alphabetical order, and includes Caesar ciphers, Virginia ciphers, substitution ciphers, shift ciphers, column substitution ciphers, and multi-table substitution ciphers.

These ciphers have become obsolete in modern cryptography because their encryption methods are not considered secure enough. One of them, Caesar cipher, uses single letter substitution and can be easily cracked by blasting etc. if the encryption offset is fixed. The Virginia cipher, on the other hand, uses multiple table substitutions, but is also easily broken if the secret key is too short or correlated.

Value of Classical Cryptography:

1. Historical Value

Classical cryptography is an important part of cryptography, which reflects the early research and application of encryption technology by human beings. By studying classical cryptography, you can gain an in-depth understanding of the historical development and evolution of cryptography, and master the basic knowledge and theory of cryptography.

2. Research Value

Although classical cryptography has been replaced by modern cryptographic algorithms, it still has certain research value. For example, in the field of password cracking, players need to use various means to try to crack classical passwords, which helps to improve the research level of cryptography.

3. Teaching value

Classical ciphers are one of the simplest and easiest to understand encryption methods in cryptography, so they are often used as introductory course content in cryptography teaching. By learning classical ciphers, students can have a preliminary understanding of encryption principles and methods, laying the foundation for subsequent in-depth research.

4. Competition Value

Classical cipher is one of the commonly used topics in CTF and other network security competitions, where players need to crack the cipher by various means to improve their skills. At the same time, it can also be used as an important content of cryptography competitions, mathematical modeling and other competitions.