Cryptography Reference
In-Depth Information
Degree of the polynomial
Primitive polynomial
α
2
+
α
+1
2
α
3
+
α
+1
3
α
4
+
α
+1
4
α
5
+
α
2
+1
5
α
6
+
α
+1
6
α
7
+
α
3
+1
7
α
8
+
α
4
+
α
3
+
α
2
+1
8
α
9
+
α
4
+1
9
α
10
+
α
3
+1
10
Table 4.9 -
Examples of primitive polynomials
Galois field
F
16
being made up of 16 elements, the binary representation of
an element of this field is done with the help of 4 binary symbols belonging to
F
2
. These 4 symbols are equal to the values taken by coecients
a
,
b
,
c
and
d
respectively.
Elements
of the
field
Polynomial
representa-
tion
Binary representation
0
0
0000
1
1
0001
α
α
0010
α
2
α
2
0100
α
3
α
3
1000
α
4
α
+1
0011
α
5
α
2
+
α
0110
α
6
α
3
+
α
2
1100
α
7
α
3
+
α
+1
1011
α
8
α
2
+1
0101
α
9
α
3
+
α
1010
α
10
α
2
+
α
+1
0111
α
11
α
3
+
α
2
+
α
1110
α
12
α
3
+
α
2
+
α
+1
1111
α
13
α
3
+
α
2
+1
1101
α
14
α
3
+1
1001
Table 4.10 -
Different representations of the elements of Galois field
F
16