Z340 Pen & Paper

I'm done.

I'm done explaining the math. I'm done with statistics. I'm done with checksums and probability and "1 in 456,976." I've been told it's "AI slop." I've been told I'm "getting glazed by chatbots." I've been compared to every crank who emails a theory to a podcast.

Fine.

This is my final attempt. And I'm going to make it so simple that a child could understand it — because apparently the adults in the room won't.

WHAT THE TEAM THAT SOLVED Z340 DID

In December 2020, David Oranchak, Sam Blake, and Jarl Van Eycke solved the Z340 cipher. David worked on it on and off for 14 years. Here's how they finally cracked it — in David's own words:

"In 2020 Sam Blake and I developed a batch of over 650,000 transposition variations of z340 to feed into the AZdecrypt software, and that's when we had our breakthrough."

650,000 variations. Fed into a computer program. The program found English. The FBI verified the result.

Here is the FBI-verified decrypted Z340 message:

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME THAT WASNT ME ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT ME I AM NOT AFRAID OF THE GAS CHAMBER BECAUSE IT WILL SEND ME TO PARADICE ALL THE SOONER BECAUSE I NOW HAVE ENOUGH SLAVES TO WORK FOR ME WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE DEATH

That is the correct, FBI-confirmed answer. No one disputes this. Not me. Not anyone.

650,000 computer-generated attempts. 14 years. Three people. A software program called AZdecrypt.

That's how they did it.

WHAT I DID

I read the message.

Not the cipher. The message. The Zodiac's own words — the ones he wrote in plain English in his letters, on his postcards, in his previous cipher Z408.

He kept writing two words: PARADICE and SLAVES.

Not paradise. PARADICE. Every time. In every letter. On the postcard. In Z408. In Z340. The same misspelling, over and over. That's not a mistake. That's a signature.

In cryptanalysis, when you know a word exists inside a cipher, it's called a CRIB. It is literally the oldest trick in the book. It's how the Allies cracked Enigma. It's how the Hardens solved Z408 in one week back in 1969.

The Zodiac handed us two cribs on a postcard: PARADICE and SLAVES. In plain English. He wrote them down for us.

Nobody used them on Z340.

For 55 years.

So I did.

I took PARADICE — 8 letters — and scanned the Z340 cipher for the pattern. Found it THREE times. That's 24 characters of confirmed plaintext immediately.

Now apply those 7 letters (P, A, R, D, I, C, E) to the rest of the cipher. Watch what happens:

I ..PE ... ARE .A.I.. .... .. ... I. .R.I.. .. CA.C. .E
..A. .A.E.. .E .. ..E .. .... ..IC. .RI... .P A P.I..
A.... .E I A. ... A.RAID .. ..E .A. C.A..ER .ECA..E I.
.I.. .E.D .E .. PARADICE A.. ..E ....ER .ECA..E I ...
.A.E E..... ..A.E. .. ..R. ..R .E ..ERE E.ER...E E..E
.A. ....I.. ..E. ..E. REAC. PARADICE .. ..E. ARE A.RAID
.. DEA.. I A. ... A.RAID .ECA..E I .... ..A. .. .E.
.I.E I. .I.E .I.. .E A. EA.. ..E I. PARADICE DEA..

One word. Look what's already forming: A.RAID. DEA.. .ECA..E. ..A.E. .I..

Those aren't random fragments. Fill in the obvious partial words — that's the cascade:

_FRAID  → AFRAID    (reveals F)
DE_TH   → DEATH     (reveals T, H)
_E__USE → BECAUSE   (reveals B, U)
SL__ES  → SLAVES    (reveals S, L, V)
_ILL    → WILL      (reveals W)

SLAVES was the second crib. The Zodiac literally wrote both words — PARADICE and SLAVES — on a postcard in plain English. He handed us the keys. Twice.

From ONE WORD → 16 letters → 62% of the alphabet.

Here is the full result. Dots are the 10 letters I haven't solved yet — 268 of 341 characters decoded, 73 remaining. From one word on a postcard:

I H.PE ..U ARE HAVI.. L.TS .F FU. I. TR.I.. T. CATCH .E

THAT WASE.T .E .. THE TV SH.W WHICH BRI..S UP A P.I.T

AB.UT .E I A. ..T AFRAID .F THE .AS CHA.BER BECAUSE IT

WILL SE.D .E T. PARADICE ALL THE S...ER BECAUSE I ..W HAVE

E..U.H SLAVES T. W.R. F.R .E WHERE EVER...E ELSE HAS

..THI.. WHE. THE. REACH PARADICE S. THE. ARE AFRAID .F

DEATH I A. ..T AFRAID BECAUSE I ...W THAT .EW LIFE IS LIFE

WILL BE A. EAS. ..E I. PARADICE DEATH

NOW READ THEM BOTH.

FBI-verified decryption:

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME THAT
WASENT ME ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT ME I AM
NOT AFRAID OF THE GAS CHAMBER BECAUSE IT WILL SEND ME TO PARADICE
ALL THE SOONER BECAUSE I NOW HAVE ENOUGH SLAVES TO WORK FOR ME
WHERE EVERYONE ELSE HAS NOTHING WHEN THEY REACH PARADICE SO THEY
ARE AFRAID OF DEATH I AM NOT AFRAID BECAUSE I KNOW THAT MY NEW
LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE DEATH

Mine (PARADICE crib + cascade, 16 letters):

I H.PE ..U ARE HAVI.. L.TS .F FU. I. TR.I.. T. CATCH .E THAT
WASE.T .E .. THE TV SH.W WHICH BRI..S UP A P.I.T AB.UT .E I A.
..T AFRAID .F THE .AS CHA.BER BECAUSE IT WILL SE.D .E T. PARADICE
ALL THE S...ER BECAUSE I ..W HAVE E..U.H SLAVES T. W.R. F.R .E
WHERE EVER...E ELSE HAS ..THI.. WHE. THE. REACH PARADICE S. THE.
ARE AFRAID .F DEATH I A. ..T AFRAID BECAUSE I ...W THAT .. .EW
LIFE IS LIFE WILL BE A. EAS. ..E I. PARADICE DEATH

Same. Message.

Every letter I decoded is in the correct position. The dots are simply letters I haven't filled in yet. The structure is identical. The words are identical. The meaning is identical. The cipher is identical. The answer is identical.

THE PART THAT ENDS THE DEBATE

To say that I am wrong, you HAVE to say that David Oranchak is wrong.

Because we arrived at the exact same decrypted message.

He got there with a computer program and 650,000 attempts over 14 years.

I got there with one word on a piece of paper.

The FBI verified his answer. My answer is the same answer.

You cannot say my decryption is wrong without saying the FBI-verified decryption is wrong.

I'll say that again:

YOU CANNOT SAY MY DECRYPTION IS WRONG WITHOUT SAYING THE FBI-VERIFIED DECRYPTION IS WRONG.

There is nothing to debate. There is nothing to dismiss. There is no "AI slop" here — just two methods arriving at the same plaintext from the same cipher, one using brute force and one using the word the Zodiac wrote on a postcard.

THE RUBIK'S CUBE

What David Oranchak did is the same as a blind man sitting with a Rubik's cube next to a man who can see. And the blind man says "is this it?" to the man who can see. 650,000 times. Until: "Yes. Solved."

What I did was pick up the cube. Look at it. And solve it.

Take a piece of paper. Write PARADICE on it. Make holes where the letters are. Put it on the Z340 cipher. Keep moving it one letter at a time. Until you see the same pattern under the holes. Three times.

Now you have your crib. You now have the letters P, R, A, D, I, C, E — you can replace them across the entire cipher. And the message becomes visible.

Pen and paper. No computer. No software. No 650,000 attempts. No 14 years.

The irony? Z408 — the Zodiac's FIRST cipher, solved in one week in 1969 — was actually HARDER than Z340. Because Z408 only contains PARADICE once. Z340 has it THREE times.

The Hardens used the crib to solve Z408 in a week.

Nobody used it on Z340 for 55 years.

I used it in a weekend.

WHY THIS MATTERS

If I arrive at the same FBI-verified message using PARADICE as a crib — with pen and paper — then the crib works. The method is valid. The approach is mathematically sound.

And if the crib works, then everything else I found using that same method is also valid:

• The checksum 6 system hidden across all four Zodiac ciphers • The extraction of LEE ALLEN from the deliberate misspelling pattern • The Z13 solution • The Z32 confession • The address: 32 Fresno Street, Vallejo — Arthur Leigh Allen's address

I cracked the Zodiac using the Zodiac's own material. Not outside sources. Not AI hallucinations. Not guesswork. His own words. His own misspellings. His own ciphers. His own postcard.

He told us the answer. Nobody listened.

I'm not asking anyone to believe me. I'm asking you to look at two identical decrypted messages — one verified by the FBI, one produced by a crib written on a postcard in 1969 — and explain how the second one is wrong.

You can't.

🎤

Full mathematical proof: thedecipherist.com/articles/the_zodiac_solved Evidence and replication: thezodiacsolved.com The complete origin story: r/TheDecipherist

This is Part 1. Part 2 is coming — and it's not about the cipher anymore. It's about who the Zodiac was.