Alberti Cipher Online Encoder

Experience Leon Battista Alberti's revolutionary 1467 polyalphabetic cipher with our interactive visual cipher disk. First encryption method to defeat frequency analysis.

"HELLO"→"URYYB"(Disk Position k→A)
Disk Cipher
Result
0 characters
Range: 0-25 (A → A)
Every 3 characters

Alberti Cipher Disk

Current Shift: 0

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
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Current Mapping

A→A
B→B
C→C
D→D
E→E
F→F
G→G
H→H
I→I
J→J
K→K
L→L
M→M
N→N
O→O
P→P
Q→Q
R→R
S→S
T→T
U→U
V→V
W→W
X→X
Y→Y
Z→Z

Advanced Alberti Cipher Tools

Advanced Decoder

Decrypt Alberti cipher messages with cryptanalysis and frequency analysis

  • • Automatic key sequence detection
  • • Index of coincidence analysis
  • • Manual disk position control

Examples & Tutorials

Learn with historical examples and interactive step-by-step tutorials

  • • "La guerra si farà" original example
  • • Interactive cipher disk lessons
  • • Practice challenges by difficulty

3D Cipher Disk

Experience the original cipher disk with realistic 3D visualization

  • • Interactive disk rotation controls
  • • Historical accuracy simulation
  • • Real-time encryption demonstration

Frequently Asked Questions About Alberti Cipher

How does Alberti cipher work?

Alberti cipher uses two concentric disks - a fixed outer disk with standard alphabet and a rotating inner disk with mixed alphabet. Encryption involves setting an index position and rotating the inner disk during encryption to create polyalphabetic substitution.

What makes Alberti cipher different from Caesar cipher?

Unlike Caesar cipher's single alphabet shift, Alberti cipher uses multiple alphabet substitutions that change during encryption, making it resistant to frequency analysis attacks.

What are the numbers 1-4 used for in Alberti cipher?

The numbers 1-4 on Alberti's cipher disk were used for encoding common words or phrases. They served as shorthand substitutions to speed up encryption of frequently used terms.

Is Alberti cipher truly unbreakable?

While not truly unbreakable by modern standards, Alberti cipher was revolutionary for its time as it defeated frequency analysis - the primary cryptanalysis method available in the 15th century.

How do you change the key during encryption?

In authentic Alberti cipher, the sender rotates the inner disk at predetermined intervals or when encountering specific trigger letters, then indicates the new position using index letters.