buttcrack. Cipher Wiki

Trifid

From the Buttcrack Cipher Wiki — the free field guide to classical ciphers

Trifid — Bifid in three dimensions: three coordinates per letter in a 3x3x3 cube, recombined within a period, so every output letter depends on three inputs.

Three coordinates per letter in a 3x3x3 cube, recombined within a period. Experimental solver.

A worked example§

Encrypting a sample with the cipher itself, at build time:

MEET ME BY THE OLD CLOCK TOWER AT DAWN

Key: key=TRIFID, period=5

produces the ciphertext

GDYPUIAYBRDIWZLKHZDGNINLXTVLSV

This example is generated by running the cipher when the page is built, and the round trip is checked, so it always matches what the solver does.

How it is broken§

The strongest fractionation in this collection, and the hardest to attack from nothing: the 27-cell cube and the period have to be recovered together.

History and context§

Delastelle's last cipher, published posthumously in 1902.

See also§

Playfair · Bifid · Hill cipher (matrix) · Four-square

Browse every cipher in the Polygraphic ciphers family, read the history of codebreaking, or return to the wiki main page.

Frequently asked questions§

How is the Trifid broken?

The strongest fractionation in this collection, and the hardest to attack from nothing: the 27-cell cube and the period have to be recovered together.

What key does the Trifid use?

keyword + period. The keyspace is unbounded in practice.

How much ciphertext do I need?

At least 90 characters for this solver to attempt it; short messages can be readable and still not be proof.

Can I break a Trifid on this page?

Not with the browser build, which targets the common puzzle families. The desktop version searches it: see the Windows app page.

Categories: Polygraphic ciphers | Full-version ciphers | Cipher wiki
The facts in this article are generated from buttcrack's cipher registry when the site is built, so they describe the implementation you can run on this page. Registry-generated content is checked against the code; the history is editorial.

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What this browser solver can—and cannot—do

It tries: Caesar, Atbash, ROT13, affine, Trithemius, rail fence, single-byte XOR, periodic Vigenère-family ciphers, autokey, selected encoding layers (such as Base64, hex, binary, decimal ASCII, Morse, and reverse), and—only with 60+ A–Z letters—statistical substitution.

It does not: prove a decryption, cover every classical cipher, or break modern encryption such as AES or RSA. Its ranking model is tuned for English, so a high score is a lead to verify with the method, key, and source context—not a guarantee.

Short text, non-English plaintext, non-Latin or symbol alphabets, missing keys, and unsupported formats can all leave no high-confidence answer. When that happens, the result includes input-specific observations and suggested next checks; those observations are not a claim to know the exact cause.

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