A lot of codes are simple in design. Just by changing the order of words, letters, or the way you read them can turn a message into a secret code. Translating messages into code is called encoding. Translating messages into ciphers is called enciphering. When you attempt to figure out what a secret message is you are decoding or deciphering. To decode you need a code book.
Get rid of spaces and returns to lump words together. Use upper case letters to make the code harder to read and decode.
Answer: I BET THIS IS HARD FOR MANY PEOPLE.
Block letters of a message by 2, 3, or more characters.
IL IK EI CE CR EA M.
After combining all of the letters above you get "ILIKEICECREAM." Looking for words in the message you'll find "I LIKE ICE CREAM."
Writing words, sentences, or entire message backwards can be very confusing!
EES UOY TA EHT EROTS.
Reading EES backwards yields the answer SEE. The answer to this encrypted message is "SEE YOU AT THE STORE."
Choose a mathematical algorithm or pattern to create or decipher a secret message from a plain message. This example uses a pattern to make a secret message: D id e veryone a t the h ouse ...etc. "DEATH" is the secret message with the words in this message.
Next time you sit down and read the newspaper use a pin to make tiny holes under letters as you read. By making a series of pin pricks in the paper, barely visible to the eye, you can actually create a message for your friends to decipher. rath (@defunkt), PJ Hyett (@pjhyett), and Tom Preston-Werner (@mojombo) founded GitHub.
A simple and free HyperCard 2.1 stack that illustrates how Napier's Bones are used as a calculator. Authored by Ken Dunham, 1994.
This is a free program that presents users with an enciphered message using random alphabet substitution. It's easy to use, free, and a great addition to the Macintosh computer use aspect of the cryptology unit.
I have a set of comprehensive lessons, over 50, along with teacher plans, objectives, and three software packages for the Macintosh platform: CryptoMath, CryptoCreator, and Map Cipher Maker. This package is now a commercial product.
This program is part of a copyrighted book "The HyperCard Roundup," co-authored by Ken Dunham and Sharon Porter. It illustrates how ASCII values are used to translate uppercase and lowercase letters into the opposing text case. It is included with the book, still unpublished, as a free utility for transforming uppercase documents into normally formatted documents with upper and lower case text. Contact Ken Dunham if you are interested in a copy.
A Cryptology FAQ is available online via newsgroups but is fairly technical regarding modern encryption processes used by computers in today's market. This document may be more appropriate for computer science majors at the university level.