Answer Happy

Affine Cipher
You have found parts of a plaintext/cipertext pair you
suspect was encrypted with an affine cipher (the * mark unreadable
letters):
c l * * * e d
M P Q M G E V
a) Determine the decryption key (see below or appendix A
for letter/number/inverses, and appendix B for multiplication table
modulo 26). Show your work.
Letter
a
b
c
d
e
f
g
h
i
j
k
l
m
n
x
0
1
2
3
4
5
6
7
8
9
10
11
12
13
x-1 26
/
1
/
9
/
21
/
15
/
3
/
19
/
/
Letter
o
p
q
r
s
t
u
v
w
x
y
z
x
14
15
16
17
18
19
20
21
22
23
24
25
x-1 26
/
7
/
23
/
11
/
5
/
17
/
25
b) Apply the decryption key, to find the secret word.
Show your work.
Letter
a
b
c
d
e
f
g
h
i
j
k
l
m
n
x
0
1
2
3
4
5
6
7
8
9
10
11
12
13
x-1 26
/
1
/
9
/
21
/
15
/
3
/
19
/
/
Letter
o
p
q
r
s
t
u
v
w
x
y
z
x
14
15
16
17
18
19
20
21
22
23
24
25
x-1 26
/
7
/
23
/
11
/
5
/
17
/
25