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Caesar & Vigenère Cipher

v1.0.1

Encrypt and decrypt text with classical substitution ciphers — Caesar, Vigenère, ROT13, Atbash, and Affine — with brute-force and frequency analysis.

Encrypt and decrypt text using classical substitution ciphers — Caesar, Vigenère, ROT13, Atbash, and Affine — with brute-force and letter-frequency analysis for unknown shift values.

How to use
  • →Select the cipher type, then enter your text and key (or shift number for Caesar).
  • →Use the Brute Force tab to try all 25 Caesar shifts at once when the key is unknown.
  • →Frequency analysis highlights the most likely key for longer Vigenère ciphertexts.
  • →Try a preset from the example picker to see classic cipher examples.
3
A↓D
B↓E
C↓F
D↓G
E↓H
F↓I
G↓J
H↓K
I↓L
J↓M
K↓N
L↓O
M↓P
N↓Q
O↓R
P↓S
Q↓T
R↓U
S↓V
T↓W
U↓X
V↓Y
W↓Z
X↓A
Y↓B
Z↓C
Input
Output
Result will appear here…