Polynomial Functions

Cryptology is the study of making and breaking secret codes. Secret codes are often used to send messages over the Internet. By devising a code that is difficult to break, the sender hopes to prevent the messages from being read by an unauthorized person. In practice, complicated one$-$to$-$one functions and their inverses are used to encode and decode messages. The following procedure uses the simple function $f(x)=2x-1$ to illustrate the basic concepts that are involved. Assign to each letter of the alphabet, and a blank space, a two$-$digit numerical value, as shown below.

$\backslash$table$[[$A$),$is$,11,17,6,24,V$