Classical Ciphers
Historical encryption methods that have shaped the foundation of modern cryptography. These ciphers offer insight into the evolution of secret communication techniques throughout history.
Caesar Cipher
A simple substitution cipher where each letter is shifted by a fixed number of positions in the alphabet. Named after Julius Caesar.
Vigenère Cipher
A polyalphabetic substitution cipher that uses a keyword to determine multiple shift values, making it stronger than Caesar cipher.
Autokey Cipher
An improvement on the Vigenère cipher that uses the plaintext itself as part of the key, eliminating key repetition.
ROT13
A special case of the Caesar cipher with a fixed shift of 13 places. Commonly used to hide spoilers and obfuscate text.
Atbash Cipher
An ancient Hebrew cipher where each letter is replaced with its mirror letter from the end of the alphabet (A↔Z, B↔Y, etc.).
Rail Fence Cipher
A transposition cipher that writes the message in a zigzag pattern across multiple rails, then reads it off in rows.
About Classical Ciphers
Classical ciphers represent the earliest forms of cryptography, dating back thousands of years. While these methods are no longer suitable for securing sensitive information in the modern world, they serve as excellent educational tools for understanding the principles of encryption.
Most classical ciphers fall into two main categories:
Substitution Ciphers
Replace each letter with another letter or symbol according to a fixed system. Examples include Caesar, Vigenère, and Atbash ciphers.
Transposition Ciphers
Rearrange the letters of the plaintext according to a specific pattern. The Rail Fence cipher is a classic example of this approach.
These ciphers were used throughout history by military leaders, diplomats, and secret societies. While easily broken with modern computational methods, they remain valuable for understanding cryptographic concepts and for educational purposes.