Question

Using a substitution cipher that skips by 7 characters, encrypt the message COMPUTERSCIENCE4ALL. For the input alphabet use 26 uppercase letters followed by 10 digits numbered 0 through 9.

I have encrypted an English phrase using a substitution cipher that has an input alphabet of 26 uppercase letters. My cipher has skipped by N letters. You may assume that the most common letters in the English language are E T A O I N

Sentence: LJWRPDNBBCQNARPQCJWBNA

Answer 1

SOLUTION

2)

Answer

CANIGUESSTHERIGHTANSER

Explanation

it was skipped by 9 letters

L

J

W

R

P

D

N

B

B

C

Q

N

A

R

P

Q

C

J

W

B

N

A

C

A

N

I

G

U

E

S

S

T

H

E

R

I

G

H

T

A

N

S

E

R

you can see N is repeating 3 times

we can replace N by E

from that we can know that number of letters skipped

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1)

First construct table

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

0

1

2

3

4

5

6

7

8

9

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

G

H

COMPUTERSCIENCE4ALL

C

O

M

P

U

T

E

R

S

C

I

E

N

C

E

4

A

L

L

K

W

U

X

2

1

M

Z

0

K

Q

M

V

K

M

C

I

T

T

Answer

K   W   U   X   2   1   M   Z   0   K   Q   M   V   K   M  C   I   T   T

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all the best