LIVE · KRYPTOS K1 WALKTHROUGH
K·R·Y·P·T·O·S // CHAPTER 01 OF 06 //
PANEL · K1
63 characters
CIPHER METHOD
VIGENÈRE / keyed alphabet
STATUS
SOLVED / 1999 · gillogly
01THE PANEL

Thirty-five years ago,
this showed up at CIA Langley.

Four panels of carved copper. 865 letters and 4 question marks of nonsense. The first one — K1 — looks like this:

K1 · 1990 · CIPHERTEXT // 63 chars · carved in copper · langley va
EMUFPHZLRFAXYUSDJKZLDKRNSHGNFIVJ
YQTQUXQBQVYUVLLTREVJYQTMKYRDMFD
// vigenère · keyed alphabet · poly-alphabetic substitution // → next: what's a vigenère?
LIVE · KRYPTOS K1 WALKTHROUGH
K·R·Y·P·T·O·S // CHAPTER 02 OF 06 //
02THE 500-YEAR-OLD IDEA

First, the cipher cryptographers
used for five centuries.

Pick a keyword. Write it under your message, repeating until it covers everything. Each plaintext letter gets shifted by the matching key letter. A=0, B=1, … Z=25.

PLAINTEXT
H
E
L
L
O
KEY · "BCDEF" (repeating)
B
C
D
E
F
CIPHERTEXT ( = plain shifted by key)
I
G
O
P
T
H (7) + B (1) = 8 → I
E (4) + C (2) = 6 → G
L (11) + D (3) = 14 → O
L (11) + E (4) = 15 → P
O (14) + F (5) = 19 → T
// each letter rides a different shift — that's why
// it's called poly-alphabetic. one cipher, many shifts.
// classical vigenère · alphabet a–z · invented 1553 // → but sanborn changed one thing.
LIVE · KRYPTOS K1 WALKTHROUGH
K·R·Y·P·T·O·S // CHAPTER 03 OF 06 //
03THE TWIST

The alphabet isn't A–Z.

Sanborn pulled K, R, Y, P, T, O, S to the front and let the rest of the alphabet trail behind, skipping any letter already used. That single change broke every off-the-shelf Vigenère solver.

KRYPTOS ALPHABET · KEYED · CARVED ON THE RIGHT-HAND PANEL OF THE SCULPTURE
K
0
R
1
Y
2
P
3
T
4
O
5
S
6
A
7
B
8
C
9
D
10
E
11
F
12
G
13
H
14
I
15
J
16
L
17
M
18
N
19
Q
20
U
21
V
22
W
23
X
24
Z
25
Now K sits at position 0, R at 1, … Z at 25. Every shift in K1 is computed in this ordering — not the usual one.
// it was hiding in plain sight on the sculpture itself.
// nobody noticed for nine years.
// quagmire III variant · keyed alphabet "KRYPTOS" · 26 positions // → now we encrypt one letter, slowly.
LIVE · KRYPTOS K1 WALKTHROUGH
K·R·Y·P·T·O·S // CHAPTER 04 OF 06 //
04WALK · ONE LETTER

Watch a single letter get encrypted.

K1's plaintext begins BETWEENSUB · its key is PALIMPSEST. Just the first letter:

PLAINTEXT
B
INDEX 8
+
KEY
P
INDEX 3
=
CIPHERTEXT
E
INDEX 11
// the math
B at index 8 in KRYPTOS alphabet
P at index 3 in KRYPTOS alphabet
━━━━━━━━━━━━━━━━━━
8 + 3 = 11
// position 11 in KRYPTOS = E
KRYPTOS ALPHABET · POSITIONS
K
0
R
1
Y
2
P
3
T
4
O
5
S
6
A
7
B
8
C
9
D
10
E
11
F
12
G
13
H
14
I
15
J
16
L
17
M
18
N
19
Q
20
U
21
V
22
W
23
X
24
Z
25
// one letter down. now do it ninety-six more times. // → next: the whole row.
LIVE · KRYPTOS K1 WALKTHROUGH · INTERACTIVE
K·R·Y·P·T·O·S // CHAPTER 05 OF 06 //
05SAME TRICK · EVERY LETTER · STEP BY STEP

Now do it for all 63 letters of K1.

Four sub-steps per letter: ① find PLAIN  ② find KEY  ③ ADD  ④ READ  · press NEXT repeatedly, or AUTO to watch.

PLAINTEXT
KEY · PALIMPSEST
CIPHERTEXT
KRYPTOS ALPHABET · POSITIONS // click NEXT or press → to begin
// what we're doing
Press NEXT → to begin. We'll encrypt the full K1 ciphertext — all 63 letters, one tiny step at a time.
// the math
letter 1 of 63 — not started
// STEP 0 / 252  ·  LETTER 0 / 63
// 63 letters · same trick · every column · carved in copper // → next: what does it actually say?
LIVE · KRYPTOS K1 WALKTHROUGH
K·R·Y·P·T·O·S // CHAPTER 06 OF 06 //
06THE ANSWER

What does K1 say?

EMUFPHZLRFAXYUSDJKZLDKRNSHGNFIVJ
YQTQUXQBQVYUVLLTREVJYQTMKYRDMFD
↓ DECRYPTS TO
Between subtle shading and the absence
of light lies the nuance of iqlusion.
↑ "IQLUSION" — not a typo. Sanborn misspelled it on purpose, partly to defeat frequency-analysis solvers, partly to draw attention to the idea of hidden meaning.
// k2: same trick, key ABSCISSA. k3: a transposition cipher. nsa cracked all three internally by 1993; gillogly published in 1999.
// the punchline
K4 · 97 characters · resisted for 35 years · solved 2025.
kryptos.today / ciphers
// k1 solved 1999 · plaintext: betweensubtleshading… // ↩ press R to restart · ← → to navigate