A Lesson in Ciphers # 7 Mystery Cache

This cache series is designed to give you an introduction to the world of ciphers. It will not cover every type of cipher out there, instead focusing on a small variety of different ciphers. Hopefully, you will walk away from solving this series with a new set of puzzle solving skills. And maybe, just maybe, you'll be able to go to that puzzle that's always bothered you and begin to see it with a new pair of eyes.

I have designed this series such that you will not be able to solve them all in one swipe. How you may ask? Outside of the first two caches, all of the caches in the series will require clues left within previous caches. I recommend that you keep track of these clues, and which cache they were found within, as you work your way through the series. That information will be useful even after you solve the cipher it is used with. On to the cache.

Before explaining the value of keys, I’ll add four more terms to our lessons. First is plain text, or PT. Plain text is the original message you want to encipher. Second is cipher text, or CT. Cipher text is the encoded message. Third is plaintext alphabet, or PA. Fourth is keyed alphabet, or KA. In cryptology, the alphabets often refers to the arrangement of letters used to turn PT into CT. It’s the alphabets that involve the key. They look like this:

PA: 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
KA: 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

The PA nothing more than the actual alphabet from A to Z. For simple ciphers, the KA is the same. Before enciphering the PT, make sure the KA is shifted over with relationship to the PA so that A doesn’t equal A, B doesn’t equal B, and so on. As long as you know how far to shift the alphabet, these ciphers are usually the simplest to decipher. Just solve one letter and you can write out the alphabet and quickly decipher the CT.

However, throw in a key and things change a bit. Keys are used so that when you create the alphabet, it affects the order of the letters. Start by writing out your key. Then write the rest of the alphabet from A to Z, skipping over letters that are in the key. Again, remember to shift the alphabet so that letters aren't equal to themselves. Line it up with a normal alphabet and begin turning your PT into CT. Voila, your CT is now harder to decipher without the key. Here is an example, after shifting the letters:

PA: 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
KA: v w x y z s a m p l e b c d f g h i j k n o q r t u

Usually, PA and KA are used with substitution ciphers. Since transposition ciphers rely on rearranging things, their keys work a bit differently. Of course, even if you know what the key is, if you do not know how the CT was enciphered, you still have a long way to go in deciphering the message.

Use a key from a previous lesson to decipher the following text. Then go find the cache to complete the lesson.

98 62 50 80 10 45 83 16 05 16 40 65 50 21 10 00 79 02 35 53 04 65 96 36 49 85 70 11 63 45 06 61 50 10 57 61 02 79 00 44 96 91 02 48 62 88 36 15 67 61 06 44 36 85 90 03 11 26 48 67 05 83 02 53 67 19 11 81 62 40 79 50 16 70 11 54 80 86 48 10 00 10 02 30 80 17 28 40 08 59 93 37 77 45 62 41 57 10 38 03 45 65 23 84 43 74 42 08 14 80 17 44 52 16 68 46 12 53 83 19 92 14 53 25 11 79 85 32 06 61 96 14

As always, be wary of muggles and try to rehide this as you found it. Parking is nearby.

Need a refresher on a previous lesson? Here's the complete list (updated as the lessons become available):