There are many ways to make a secret note. Depending on the secrecy of what you have to say, these ways can vary drastically. Here are a few ways to make a secret note easily and virtually indecipherable. The only problem is that the receiver has to know the code, too!
Step 1
Create a new language. If the secret note is to one person (or a small group), you can create a "language" where each letter is replaced by a symbol. Make sure the person knows the code, or include a list of each symbol and what it stands for. It should be easy enough to remember, but mysterious enough so you can't easily translate it. (For example, A=1, B=2, C=3 is too easy a code. A better code would be a swirl for A, a triangle for B, a star for C, etc.)
Step 2
Make it hidden. Dip a paintbrush in milk/lemon juice and write your message on a white piece of paper. Let dry. To decode, heat the paper with a hair dryer. You can also use lemon juice and heat it with a hair dryer as well. It is a really good method.
Step 3
Substitute a letter to another. Substitution codes is when a letter stands for a different letter. A = Z is too easy. Try random combinations like M = B. It's a lot harder to decode when all the letters are put together in one long string of letters.
Step 4
Use transposition. For example: "That is a large amount of corn, John" becomes "tsrof,h-gu--aaencjt--too-la-rhiamonn". For those wondering how this works, try writing the original sentence into a 6x6 table like this. Now read it vertically.
Step 5
Follow the snake method. Similar to the transposition method, the snake method requires you to just arrange the letters upwards and downwards, like a snake. After completing it, just sign a small snake signature to indicate that you have used the snake method.
Step 6
Coat it with cellotape Cover a PLAIN piece of paper with cellotape.Write your message on in felt tip. If your teacher spots your friend reading the note your friend can rub it off before he/she can get there.
Tips
- Try to think of a secret code that would be hard for interceptors to figure out, but easy for you and your receivers to decode.
- Also, when sending try to avoid contact with people you don't want to read the contents.
- Another code (a bit too easy for people who understand that it's a code) would be this:
- Hi bob! would be !oiHbb
- and 12345678 would be 86421357, starting at the end, and listing every other number, and then going back, listing the ones you skipped.
- You can always write the note in a different language.
- Try not using spaces in your codes.
- Using spaces tells the intruder that the word contains a specific amount of letters. Eg. 8%^ !%% has a space between the words, so it tells the intruder that both the words have three letters and the second letter of the first word (%) is the same as the last two letters in the second word. Thus, he/she can guess that the code is "YOU TOO". This is a huge problem, as it also tells the intruder some amount of the symbols used for certain letters, making it easier for him/her to break the code.
- Instead, try to use symbols for spaces too. 8%^?!%% makes the code a lot harder to crack. Hyphens and underscores are too easy to find, so try to use actual symbols that look like they represent letters. The group who know to decode it alone can know of the symbol representing a space.
- Try doing this write a message like this:
- h i h o w a r e y o u remember the spaces next add a random letter between the real ones and the message turns into: "hji hnoaw akrme ygobu" now tell your friend about this method and to skip a letter and it turns into hi how are you study this method and it will be easy for you to read
Warnings
- While most codes (using these basic concepts) are virtually indecipherable, they can still be decoded by using trial and error, but it would take the person a very long time.
- Any code you use, you must keep in mind that given enough computer time and determination, it can be broken. There's a reason for 128-bit encryption keys (which are actually no longer considered secure). So if you don't want your secret to be known, don't put it on paper.
- Ever read The DaVinci Code or Digital Fortress? There are people who, for a living, crack secret notes and codes for various governments and private organizations. If you plan on writing something that might even hint to anything illegal, it won't take long for someone to find out what you wrote.
- Please note that wetting paper in no. 3 may make it very fragile.
