WEB-based encryption and decryption system for block substitution cryptographic ciphers

摘要

Cryptography is a mathematical science. It was established with the advent of writing. Its name comes from Greek and means the science of secret writing (kriptos-means secret; grafus-means write). Cryptography is the science that seeks to encrypt or decrypt text called plaintext. Encryption and decryption are designed to protect data from unauthorized access. With the development of information technology the need for the protection of personal user data increases. There are two main classifications of symmetric block ciphers-substitution ciphers and transposition ciphers. This paper presents a Web-based encryption and decryption system for various types of substitution ciphers. The system enables students to learn better with academic disciplines related to cryptography and data protection. It provides a short theoretical material for each type of cipher; introduces the student to the nature of the encryption and decryption of ciphers; allows encryption and decryption of multiple substitution ciphers with randomly introduced plaintext; key for encryption/decryption; allows to study the use of ciphers with feature animation.