Code Format

Note on restricted alphabets: the codebook itself will use only the characters you select, but the CODEX App’s superencipherment layers (Vigenère, Caesar, substitution, additive) operate on the full base-62 alphabet, so ciphertext will contain digits and mixed-case letters even when the underlying codebook does not. Decoding still recovers the original codes correctly. Pick a restricted alphabet mainly for aesthetics or to mimic a historical codebook style.

Vocabulary

Homophones

Higher = more homophones per token, weighted by English frequency. At 1x, common letters like “e” already get 12 codes while “z” gets 1.

Null Codes

Null codes are dummy code groups that the encoder can insert at random positions. They disrupt frequency analysis by adding noise. The decoder recognizes and silently strips them. More null codes means more variety in the inserted dummies.

Additive Pad (companion key, optional)

An additive pad is a separate one-time-use key that goes alongside the codebook. When the CODEX App is set to Additive superencipherment, it adds the pad character-by-character to every code character (mod 62), making the result statistically indistinguishable from a one-time pad. For the most realistic re-enactment, generate both a codebook and a long companion pad here, share both with your recipient, and use one chunk of the pad per message.

One-time use: never reuse a pad for another message. If you do, an attacker can XOR the two ciphertexts together to cancel the pad and recover information about both plaintexts (the “depth” attack that broke real one-time-pad systems in WWII). Generate a fresh pad — or take a fresh chunk of a long pad — for every message.

Custom Word List (optional)