Difference between revisions of "ROT13"

From Cacheopedia
Jump to: navigation, search
m (Categorized)
Line 6: Line 6:
 
ROT13 is a simple cipher used to obscure geocache hints in a way that allows a determined person to decode the hint if they want to, but makes it impossible to "accidently" read the hint (and spoil your fun).  ROT-13 can be decoded by hand with just a pencil rather quickly.  Here is the key:
 
ROT13 is a simple cipher used to obscure geocache hints in a way that allows a determined person to decode the hint if they want to, but makes it impossible to "accidently" read the hint (and spoil your fun).  ROT-13 can be decoded by hand with just a pencil rather quickly.  Here is the key:
  
<!--
 
When you ROT-13 a message, you simply replace each letter in the message with the letter that occurs 13 spaces ''after'' it in the alphabet.  If you reach Z, start over at A.  Imagine a wheel with the alphabet printed around it.  To encode a letter, find that letter on the wheel, and then ''ROT''ate the wheel ''13'' spaces.  That's it.
 
  
Of course you could ROT-1 a message if you wanted to, or any other number from 1 to 26, but 13 is special because it is half of 26, and therefore ROT-13 works to encode and decode messages as well.
+
A B C D E F G H I J K L M
 +
N O P Q R S T U V W X Y Z
  
Example:  If you encoded a message with ROT-1, you would have to use ROT-25 to decode the message.  That's because on a 26-sided wheel, 25 is the same as -1.
 
Likewise, encoding with ROT-2 would require ROT-24 to decode, ROT-3 and ROT-23.  But what about ROT-13?  It decodes itself!  This is simply because 13 is half of 26.  The fact that ROT-13 decodes itself makes it easy to setup one chart for encoding and decoding:
 
-->
 
 
<pre>
 
A B C D E F G H I J K L M
 
N O P Q R S T U V W X Y Z
 
</pre>
 
  
 
To encode or decode a letter, just find it on the chart and pick the letter above or below it as your coded letter.
 
To encode or decode a letter, just find it on the chart and pick the letter above or below it as your coded letter.
 +
 +
===Example===
 +
Ybbx va gur gerr
 +
 +
The first letter of this encrypted hint is '''Y''', Y corresponds to L on the key above.  So we know that the hint text starts with L:
 +
L
 +
The next two letters are '''bb'''.  Using the key above, we see that they become ''oo''.  '''x''' becomes ''k'', so the first word is:
 +
Look
 +
As we continue to uncode the hint, eventually we come up with this:
 +
Look in the tree.
 +
  
 
Many experienced geocachers have memorized this chart and can decode caching hints in a flash.
 
Many experienced geocachers have memorized this chart and can decode caching hints in a flash.

Revision as of 17:34, 23 November 2005

ROT13 on wikipedia.

The wikipedia article above can provide you with all the details and mathematics about ROT13, here is why it relates to geocaching.

ROT13 is a simple cipher used to obscure geocache hints in a way that allows a determined person to decode the hint if they want to, but makes it impossible to "accidently" read the hint (and spoil your fun). ROT-13 can be decoded by hand with just a pencil rather quickly. Here is the key:


A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z


To encode or decode a letter, just find it on the chart and pick the letter above or below it as your coded letter.

Example

Ybbx va gur gerr

The first letter of this encrypted hint is Y, Y corresponds to L on the key above. So we know that the hint text starts with L:

L

The next two letters are bb. Using the key above, we see that they become oo. x becomes k, so the first word is:

Look

As we continue to uncode the hint, eventually we come up with this:

Look in the tree.


Many experienced geocachers have memorized this chart and can decode caching hints in a flash.

Personal tools