1. Alberti Cipher encoder

Text : ABCD efgi
STABILIS : abcdefghijklmnopqrstuvwxyz
MOBILIS : abcdefghijklmnopqrstuvwxyz
InitialShift : 1
Increment : 2
Period : 3

Solution:

STABILIS

a

b

c

d

e

f

g

h

i

j

k

l

m

n

o

p

q

r

s

t

u

v

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x

y

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MOBILIS

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

Initial Shift = 1, So the MOBILIS disk is rotated by 1 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

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17

18

19

20

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25

STABILIS

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

MOBILIS

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

Period is 3, So Split text into pairs of 3-letters
abc def gi

a is at STABILIS-0 `=>` MOBILIS-0 is b

b is at STABILIS-1 `=>` MOBILIS-1 is c

c is at STABILIS-2 `=>` MOBILIS-2 is d

The MOBILIS disk is rotated by 2 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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 is at STABILIS-3 `=>` MOBILIS-3 is g

e is at STABILIS-4 `=>` MOBILIS-4 is h

f is at STABILIS-5 `=>` MOBILIS-5 is i

The MOBILIS disk is rotated by 2 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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

g is at STABILIS-6 `=>` MOBILIS-6 is l

i is at STABILIS-8 `=>` MOBILIS-8 is n

Plaintext	: abcdefgi
Ciphertext	: bcdghiln

---

2. Alberti Cipher encoder

Text : hello world
STABILIS : abcdefghijklmnopqrstuvwxyz
MOBILIS : abcdefghijklmnopqrstuvwxyz
InitialShift : 1
Increment : 2
Period : 3

Solution:

STABILIS

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

MOBILIS

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

Initial Shift = 1, So the MOBILIS disk is rotated by 1 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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

Period is 3, So Split text into pairs of 3-letters
hel low orl d

h is at STABILIS-7 `=>` MOBILIS-7 is i

e is at STABILIS-4 `=>` MOBILIS-4 is f

l is at STABILIS-11 `=>` MOBILIS-11 is m

The MOBILIS disk is rotated by 2 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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

l is at STABILIS-11 `=>` MOBILIS-11 is o

o is at STABILIS-14 `=>` MOBILIS-14 is r

w is at STABILIS-22 `=>` MOBILIS-22 is z

The MOBILIS disk is rotated by 2 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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

o is at STABILIS-14 `=>` MOBILIS-14 is t

r is at STABILIS-17 `=>` MOBILIS-17 is w

l is at STABILIS-11 `=>` MOBILIS-11 is q

The MOBILIS disk is rotated by 2 letters
Now Alphabets are aligned like

Number

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

STABILIS

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

MOBILIS

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

d is at STABILIS-3 `=>` MOBILIS-3 is k

Plaintext	: helloworld
Ciphertext	: ifmorztwqk