Numeric

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.