writing short messages using numbers and matrices

To encode a short message a number can be assigned to each letter of the alphabet according
to a given table. The text as a sequence of numbers will be organized into a square matrix A;
in the case that the number of letters is lower than the number of elements of the matrix A,
the rest of the matrix can be filled with zero elements. Let a nonsingular square matrix C be
given. To encode the text the matrix A can be multiplied by the matrix C for example on the
left. Let the following table and the matrix C be given:
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
8 7 5 13 9 16 18 22 4 23 11 3 21 1 6 15 12 19 2 14 17 20 25 24 10
C =  2 0 1/ 1 0 1/ 0 1 0 
We put the text ”BILA KOCKA” (a white cat) into the matrix A:
A =  7 4 3 8 /11 6 5/ 11 8 
and encode the text:
Z = CA =  19 19 14/ 12 15 11 /8 11 6/ 
To decode the message we have to multiply the matrix Z by the matrix C−1 on the left:
C−1Z =  1 1 0/ 0 0 1 /1 2 0   19 19 14/ 12 15 11 /8 11 6 / = A.
Since the matrix multiplication is not commutative, it is necessary to keep the order of
the matrices in the product. If we multiply the matrices C−1 and Z in the opposite order, we
obtain
ZC−1 =  19 19 14 /12 15 11/ 8 11 6   1 1 0/ 0 0 1 /1 2 0  = 
5 919 /1 10 15/ 2 4 11 
and it means ”CERNY PSIK”(a black
dog). Source:http://www.mff.cuni.cz/veda/konference/wds/contents/pdf06/WDS06_106_m8_Ulrychova.pdf
what did i learn: i chose this article because its very simple and useful.It helps me text message others in a simpler way and in a fast way.I liked it and i can use it on daily bases.

BY JOHN Michel HItti