Question

Use general Caesar cipher to encrypt the following plaintext

Computer science. with the key = 10.

Use general Caesar cipher to decrypt the following ciphertext

Qgtpz rdst. with the key = 15.

Attack to recover the following general Caesar code

Wdl pgt ndj.

Answer 1

Solution:

Question 1:

For key = 10:

Letters in Bold: Plain text

Letters in normal : Cipher

a	b	c	d	e	f	g	h	i	j
k	l	m	n	o	p	q	r	s	t
k	l	m	n	o	p	q	r	s	t
u	v	w	x	y	z	a	b	c	d
u	v	w	x	y	z
e	f	g	h	i	j

By using the above table

Plain text : Computer science

Cipher text : Mywzedob cmsoxmo

Question 2 and 3:

For key = 15

Letters in Bold: Plain text

Letters in normal : Cipher

a	b	c	d	e	f	g	h	i	j
p	q	r	s	t	u	v	w	x	y
k	l	m	n	o	p	q	r	s	t
z	a	b	c	d	e	f	g	h	i
u	v	w	x	y	z
j	k	l	m	n	o

Using the table

question 2:

Cipher text : Qgtpz rdst

Plain text : Break code

question 3:

Cipher text : Wdl pgt ndj

Plain text : How are you