Cryptography is a science that studies secure communication. It studies how to secretly convert the information to be transmitted before sending it to the receiver in an unsafe environment to prevent the third party from stealing the information.

Cryptography mainly includes encryption and decryption. Generally, understandable messages are called plaintext, and incomprehensible messages converted by plaintext through encryption are called ciphertext. This process is called encryption. The process of converting ciphertext into plaintext by inverse transformation is called decryption. The mutual conversion between plaintext and ciphertext is reversible, and there is only a unique and error-free reversible conversion. The algorithm to complete encryption and decryption is called cryptosystem. ?

Introduction to cryptography:

Cryptography is an ancient and profound discipline, an interdisciplinary subject combining mathematics, computer science, electronics and communication, and a science studying the security of information systems. Cryptography mainly includes two branches: cryptography and cryptanalysis. The main purpose of cryptography is to find ways to ensure information confidentiality or kernel shaping, and the main purpose of cryptanalysis is to study the decoding or forgery of encrypted messages. Cryptography has experienced the evolution from ancient cryptography to modern cryptography.

Cryptography has now developed into a comprehensive discipline including many branches, mainly cryptography, cryptanalysis and cryptography. Cryptography is a science that studies the laws of encryption algorithms and uses them to protect secret information in communication. Cryptanalysis, also known as cryptanalysis, is a science that studies the law of password change and applies it to passwords to obtain information and intelligence. Cryptography takes the key as the research object, including its generation, distribution, storage, protection and destruction.