Numeric

The Gronsfeld Cipher is a variant of the Caesar Cipher that uses a numeric key to perform multiple shifts on the plaintext. Named after the German banker Baron Gronsfeld in the 19th century, it operates like a Caesar shift but allows each letter to be shifted by a different amount based on the corresponding digit of the key.

A Dice Cipher, also known as a Dice Cryptography or a Book Cipher, is a cryptographic technique that uses dice as a randomization tool to generate a series of numbers that correspond to words or characters in a pre-selected reference book. It is a form of polyalphabetic substitution cipher.

Here's a general overview of how a Dice Cipher works:

Cicada 3301 refers to a mysterious organization that gained notoriety for releasing a series of complex internet puzzles and cryptographic challenges starting in 2012. While not a cipher itself, the puzzles prominently feature cryptography, steganography, and classical cipher techniques, including substitution, transposition, and polyalphabetic ciphers. Participants are required to decode hidden messages, uncover metadata, and traverse a series of challenges that often combine digital and real-world clues.

The Book Cipher is a classical encryption method in which numbers in the ciphertext refer to positions within an agreed-upon text, known as the key book. Instead of substituting letters directly, the cipher uses an external document as the lookup table. Without the exact same book, edition, and formatting, the ciphertext is effectively meaningless.

Book Cipher: Encoding

By default, spaces and punctuation are excluded when counting positions. Letters are indexed sequentially as a continuous stream of characters.

Using the key text:

The Beale Cipher is a set of three ciphertexts that allegedly reveal the location of a hidden treasure buried in the United States in the early 19th century. Only one of the three ciphers, commonly referred to as Beale Cipher #2, has been solved, revealing the treasure’s contents using a book cipher method.

The Affine Cipher is a type of monoalphabetic substitution cipher that combines multiplication and addition operations to transform plaintext letters into ciphertext. Each letter x in the plaintext is first converted to a numeric value, typically A=0 through Z=25, and then encrypted using the function E(x) = (ax + b) mod 26, where a and b are keys chosen such that a is coprime with 26.

The A1Z26 Cipher is a straightforward substitution cipher in which each letter of the alphabet is replaced by its corresponding numerical position. Specifically, A=1, B=2, C=3, continuing through Z=26. This simple mapping transforms plaintext into a sequence of numbers, creating a numeric representation of the original message while maintaining a direct, one-to-one correspondence between letters and values.