Number Stations

Number sequence input

Output

> Decoded results will appear here.

Ciphers

Substitution

ADFGVX

Substitution

WWI German 6x6 grid (A-Z, 0-9) + columnar transposition

Key for 6x6 square

Key for columnar transposition

Affine

Substitution

Affine transformation: E(x) = (ax + b) mod 26

Multiplier (must be coprime with 26)

Shift amount

Autokey

Substitution

Self-keying Vigenere - key extends with plaintext

Initial keyword

Beaufort

Substitution

Reciprocal Vigenere - Cipher = Key - Plaintext (mod 26)

Keyword for encryption

Bifid

Substitution

Polybius fractionation - split coordinates and recombine

Keyword for Polybius square

Book

Substitution

Page/line/word reference cipher - encodes position in book

Full book text (words separated by spaces)

Caesar

Substitution

Shift cipher - each letter shifted by a fixed amount

Shift amount (0-25)

Four-Square

Substitution

4 Polybius squares - two for plaintext, two for cipher

Keyword for top-left and bottom-right

Keyword for top-right and bottom-left

Hill

Substitution

Matrix multiplication mod 26 - block cipher

2x2 or 3x3 matrix (e.g. [[6,24,1],[13,16,10],[20,17,15]])

Nihilist

Substitution

Polybius square + modular addition with cipher key

Key for Polybius square

Key for addition

Playfair

Substitution

5x5 digraph cipher - encrypts letter pairs

Keyword for grid

Polybius Square

Substitution

5x5 coordinate encoding - each letter becomes two digits

Keyword for square (I/J combined)

Running Key

Substitution

Text passage used as key - like Vigenere with long key

Passage of text used as key

Straddling Checkerboard

Substitution

Variable-length digit mapping - 8 chars get 1 digit, 2 get 2 digits

Keyword for alphabet

Row positions for 2-digit chars (e.g. [3, 7])

Substitution

Monoalphabetic substitution - each letter maps to another

26-letter substitution alphabet (e.g. ZYXWVUTSRQPONMLKJIHGFEDCBA)

Trifid

Substitution

3D fractionation - 3x3x3 cube with period

Keyword for cube

Grouping period

VIC

Substitution

Soviet spy cipher: straddling checkerboard + transposition + chain addition

Primary key phrase

Date for chain (e.g. DDMMYY)

Agent personal number

Vigenere

Substitution

Polyalphabetic cipher using a repeating key

Keyword for encryption

Transposition

Columnar Transposition

Transposition

Write in rows, read out by column key order

Column order key

Rail Fence

Transposition

Zigzag transposition across rails

Number of rails

Stream

One-Time Pad

Stream

Modular addition with random pad - theoretically unbreakable

Random pad (letters A-Z)

XOR

Stream

XOR each byte with repeating key

XOR key