Solitaire Cipher
The Solitaire cipher, also known as the Pontifex cipher, is a manual encryption system invented by Bruce Schneier in 1999 to allow strong cryptography using a standard deck of playing cards. It functions as a stream cipher, producing a pseudo-random keystream from the deck that is then combined with plaintext letters modulo 26 to produce ciphertext. The cipher is fully reversible, so decryption uses the same keystream generated from an identically ordered deck.
Simple Substitution Cipher
The Simple Substitution cipher is one of the oldest and most straightforward encryption methods, where each letter of the plaintext is replaced with a unique corresponding letter or symbol from a fixed ciphertext alphabet. Its origins trace back to classical antiquity, with early examples appearing in the works of Julius Caesar around 58–50 BCE for basic shift substitution, and more formalized systems appearing in Europe during the Renaissance.
Scytale
The Scytale is an ancient cryptographic tool used to encrypt and decrypt messages in a simple and effective manner. It originated in ancient Greece and was primarily employed by Spartan military commanders and messengers for secure communication.
Running Key Cipher
The Running Key cipher is a classical polyalphabetic substitution cipher that extends the core idea behind the Vigenère cipher by replacing a short, repeating keyword with a long, non-repeating key text. Instead of cycling a small key like KEY, the cipher uses an entire passage of natural language, such as a book, newspaper, or letter, as the encryption key.
Rout Cipher
The Rout Cipher is a type of transposition cipher used to encrypt messages by rearranging the characters according to a specific pattern or route. It is a historical encryption method that predates modern cryptographic techniques and offers a basic level of security.
In the Rout Cipher, the plaintext is written into a grid or matrix row by row, following a predetermined route specified by the encryption key. The route could be a zigzag pattern, a winding path, or any agreed-upon sequence.
ROT Cipher
The ROT Cipher, also known as the Caesar Cipher or Caesar Shift, is one of the simplest and earliest known encryption techniques used for encoding messages. It is named after Julius Caesar, the Roman military leader who reportedly used this method to protect confidential communications during his time.
Rosicrucian Cipher
The Rosicrucian Cipher is a mysterious cryptographic method often associated with the Rosicrucian Order, an enigmatic and esoteric secret society dating back to the early 17th century. While the existence of the Rosicrucian Cipher is historically uncertain, it has been the subject of intriguing legends and myths.
Rail Fence Cipher
The Rail Fence Cipher, also know as a ZigZag or WigWag Cipher, is a transposition cipher that rearranges the letters of a message to create a new encrypted message. It gets its name from the way the letters are written in a zigzag pattern that resembles a fence made of rails.
Here's how the Rail Fence Cipher works:
Polygraphia
Polygraphia is a historical treatise on cryptography and steganography written by Johannes Trithemius, a German abbot and scholar, in the late 15th century. The word polygraphia is derived from Greek, where poly means many and graphia means writing reflecting the treatise's focus on various methods of secret writing and communication.
Polybius (Square) Cipher
The Polybius Square cipher is a classical substitution cipher invented by the ancient Greek historian and scholar Polybius around 200 BCE. It converts letters into pairs of numbers based on a 5×5 square grid, allowing plaintext to be transmitted using numbers instead of letters. Traditionally, the letters I and J are combined to fit the 25-cell grid.