What kind of beginner secret code should I use?

In My Humble Opinion
1

Okay, I live with someone now with whom I don’t have enough privacy.

I have some bulletin boards in my room on which I will be writing out stuff like

-errands that need running
-reminders
-and even planning out each day of the week in detail

And I also have a calendar with my life events planned on it for the upcoming year.

I need a secret code I can use to write things onto these things so that my housemate (who goes into my room periodically to clean, etc.) won’t be able to read them.

What would you reccomend for a beginner? Something complicated enough that no one could crack it who can solve, say, any puzzle in the newspaper (not that my housemate is; just let’s say that).

And please, no advice about asking the person nicely not to snoop; JUST CODES PLEASE. :wink:

2

  1. Straight numeric substitution? (1=a, 2=b, etc.)

  2. Do you know a foreign language?

3

Write in morse code…backwards (from right to left).

4

Why not? This seems rather a Rube Goldberg way to go about it; why not just put a lock on your door (and clean your own room), or keep your big secret plans locked in a drawer?

5

How about numeric substitution backward Morse Code in French and invisible ink?

6

Navajo

7

Get a copy of the Oxford English Dictionary and write your notes with the page number and line number of each word. Hide the O.E.D. under your pillow, or a number of your pillows.

For additional security, get a different edition every week and discard the present one.

Your housemate is going to wonder what’s up. Think of a tactful way to say, “That’s so you don’t snoop on me while you’re doing me the favor of cleaning my room.” Start looking for a new housemate.

8

Use a day planner or PDA, put it under lock and key or use a password, as appropriate. If it’s a bulletin board, you’re looking for it to remind you periodically of what is going on when you look at it briefly. Any sufficient code will be difficult for YOU to crack, at least in your head while you glance at it in passing. Use a day planner/PDA and train yourself to review it every day, and you will get all your reminders, organize your schedule and keep it private.

9

3, 1, 2
1, 3, 2
2, 3, 3
1, 2, 2
1, 2, 2
3, 1, 2
1, 3, 2
2, 3, 3
1, 2, 2
1, 2, 2

1, 1, 2
3, 3, 1
3, 1, 2
1, 3, 2
2, 3, 3
1, 2, 2
1, 2, 2
1, 3, 1
2, 3, 3
1, 3, 3
1, 2, 1
3, 1, 1
1, 2, 2
1, 1, 1
1, 1, 3
1, 3, 2

3, 1, 1
2, 3, 2
3, 1, 3
1, 1, 1
2, 3, 3
1, 2, 2

1, 1, 1

2, 1, 3
1, 2, 2
3, 1, 2
3, 1, 2
1, 2, 2
2, 3, 3
2, 3, 1
3, 1, 1
1, 3, 1
1, 2, 2
3, 1, 2
1, 1, 1
2, 1, 3
1, 3, 3
1, 2, 3
1, 2, 2

10

Use the dancing men alphabet (derived from a Sherlock Holmes story); you’ll obviously have to learn to read and write using it; you could download a free font of it here to practice:
http://www.algonet.se/~osarkab/mart_1/dancingmen/damen.html

11

Sounds to me like housemate is his mom, so that probably won’t work. Just guessing though, could be totally wrong.

How bout a Caesar cipher? Like this .

12

I think you should use extreme abbreviation. All you really need is some sort of que to remind you of what you wrote. You don’t want anyone else to read it, so write something that will only make sense to you.

For example, the preceding paragraph can be written as:

u: ab. q->r U. o.p.=?U=!

That could be about anything to a casual observer, but if you remember what you were writing about, it speaks volumes.

13

Easy - just type it up, print it off on white paper with white text, and then highlight it when you need to read it!

I see nothing wrong with this idea.

14

Using a pen with black ink, write down the notes on one side of a 3X5 notecard.
Put it in your pocket.

15

Lewis Carroll’s alphabet cipher. See the wiki article. :wink:

Advantage is that the tabel can be recreated at will from memory, and the ciphered text is nearly uncrackable without the key word, which only you (and any correspondents) must know.

The article is a little obscure about decoiding, but it’s wicked easy. Take first ciphered letter, run across the row until you meet the key letter, then go up to top of column…that’s your plain text.

So, in the article, the ciher starts with ‘h’. Go across that row to ‘v’…what’s atop that column? M, first plain text letter of the true message.

Elegant and won’t be cracked without an educated person armed with a computer.

Sailboat

16

Sorry, that whole post is mine. Not supposed to be a quote.

Sailboat

17

Pig Latin.

18

Looks like the one I’ll be going with. Thanks a bunch, everyone.

Yeah, locks would be sensible (not that expensive to get installed, either), but it’s complicated- I don’t want the housemate to think that I’m hiding something more than writing from her. It’s a complicated relationship to explain here.

19

Gonna be writing down those ideas and inventions and don’t want her to steal them, huh?

20

Interesting. Carrol’s idea was what I was going to suggest. It’s essentially an XOR over a string with a key string in a loop–just converted for 26-base.