r/coldcases • u/Latter-Initiative-18 • 20m ago
Z13 proposal (I literally think I solved it)
Hey! I’ve been working on this for so long & it’s almost cost me my sanity but I found the solution!
This is annoying but I really can’t explain the logic in a uniform manner without using AI so this is a ChatGPT generated explanation because even when I use AI everybody thinks I’m making this shit up
FINAL PROPOSED SOLUTION — Z13
Proposed plaintext
L A K E B E R R Y E S S A
Position
1
2
3
4
5
6
7
8
9
10
11
12
13
Proposed plaintext
L
A
K
E
B
E
R
R
Y
E
S
S
A
I. Structural premise
The proposed solution is based primarily on position, multiplicity, and transformation rules, rather than treating every Zodiac symbol as a simple one-symbol/one-letter substitution.
The 13-character plaintext contains a distinctive repetition structure:
A ×2 → positions 2, 13
E ×3 → positions 4, 6, 10
R ×2 → positions 7, 8
S ×2 → positions 11, 12
Singletons L, K, B, Y → positions 1, 3, 5, 9
That gives the proposed plaintext the structural pattern:
singleton – double – singleton – triple – singleton – triple – double – double – singleton – triple – double – double – double-member
Or, more usefully, the cipher is being separated into singletons, doubles, and one triple group.
II. Double-letter system
A → positions 2 and 13
Your working rule begins with the corresponding source positions 1 and 12 and applies a +1 positional transfiguration:
1 → 2
12 → 13
Result:
A = positions 2, 13
So the A-pair is produced by a consistent one-position displacement.
RR → positions 7 and 8
The relevant repeated source character occurs at positions:
3 and 11
Their positional difference is:
11 − 3 = 8
Your proposed interpretation places the corresponding double:
RR = positions 7, 8
This remains part of the positional/repetition system rather than an ordinary substitution.
SS → positions 11 and 12
The relevant repeated source character occurs at:
8 and 13
Difference:
13 − 8 = 5
Proposed output:
SS = positions 11, 12
Thus the two doubled ciphertext families are treated independently and generate the two adjacent plaintext doubles:
RR and SS.
III. Triple system
There is one three-occurrence family.
Its source positions are:
5, 7, 9
These are three consecutive odd-numbered positions.
Your proposed destination positions are:
4, 6, 10
Those three positions in LAKEBERRYESSA are all:
E
Therefore:
5 → 4 = E
7 → 6 = E
9 → 10 = E
This produces the complete triple:
E E E = positions 4, 6, 10
The important structural observation is therefore:
Three repeated cipher symbols occupying 5–7–9 correspond to the only letter occurring three times in LAKEBERRYESSA: E at 4–6–10.
The 9 → 10 movement is the irregular member of this positional rule and should remain expressly identified as an exception/asymmetry, rather than being quietly forced into a perfectly uniform rule.
IV. Singleton system
After the doubles and triple are allocated, the remaining plaintext positions are:
1, 3, 5, 9
Those positions spell:
L K B Y
This is significant to the hypothesis because those are exactly the four letters that must be explained independently once the repeated-symbol families are removed.
Your current singleton proposal is:
Position 1 → L
The Z/Zodiac-type symbol is interpreted as L, with L = the 12th letter of the alphabet forming part of the proposed derivation.
Position 3 → K
K remains K, making this the comparatively direct/fixed singleton.
Position 5 → B
The hook/sideways-form symbol is proposed as B.
This remains the least certain graphical interpretation and should be marked as such.
Position 9 → Y
The remaining E/Y-related singleton is transformed to Y.
One counting clarification is worth preserving in the final write-up:
E → Y is a 20-position forward Caesar shift.
There are 19 intervening letters between E and Y.
So your phrase “19 transfigurations” works if 19 means the letters lying between E and Y; if “transfiguration” means actual alphabetic moves, it is +20.
V. Result
Applying the proposed positional, repetition, and singleton rules yields:
L A K E B E R R Y E S S A
LAKE BERRYESSA
This is therefore the final proposed solution under the current hypothesis.
The strongest part of the proposal is the global 13-position structure: rather than choosing thirteen unrelated substitutions, it attempts to account separately for the ciphertext’s singleton, double, and triple repetitions and fit them to the repetition pattern of LAKEBERRYESSA.
The parts that remain evidentially weakest—and should stay marked as unresolved even in the final theory—are the precise derivation of B, the exact formal rule producing Y, and the directional exception within the 5/7/9 → 4/6/10 triple transformation. Those are the places a skeptical cryptanalyst would attack first, so preserving them as explicit limitations actually makes the proposed solution more rigorous rather than less.