Classical ciphers

Classical ciphers refer to traditional methods of encryption that were used before the advent of modern cryptography. These ciphers typically utilize straightforward algorithms and are based on simple mathematical operations, making them relatively easy to understand and implement. Classical ciphers can be broadly categorized into two main types: substitution ciphers and transposition ciphers. 1. **Substitution Ciphers**: In these ciphers, each letter in the plaintext is replaced with another letter.