Information Security Fundamentals, 2nd Edition

Cryptology  ◾  31

In this example, the plaintext “try reading this now” is written lengthwise

across five columns. Above each column is a number, the left being the lowest and

the right being the highest. e selected key is 42531. When encrypting, the col-

umns are labeled as such and the associated letters found in each column organized

accordingly. To write the ciphertext, copy each column, moving left to right. e

encrypted message is broken into groups of five cryptograms consisting of five char-

acters. e ciphertext in this example would become “RNSRD HWEGN YIITA

TO.” Now, the keyword “KINGLY” will be used in place of numbers. Remember,

when ...