GC1KQBQ - HBD Puzzle

GC1KQBQ - HBD Puzzle

By: Team Black-Cat

First of all, the 'very familiar' part of the description refers to an archived cache that had been placed by GetMeOutdoors many years ago.  Since GMO's archived cache was not a Traditional and none of the posted coordinates for any of his other types of archived caches matches the solved coordinates for this cache, this hint is a dead end.  This location will only be familiar to those who were actively caching around that time.

And so, on to the solution...

1.  Note the italicized letters in the description.

"This cache was placed to celebrate our son's birthday...It will take a little fiddling around..."

Put together, they spell bifid; therefore, one can assume that this puzzle utilizes a Bifid Cipher.


Here is the hyperlink to a website that describes the Bifid Cypher:

http://www.braingle.com/brainteasers/codes/bifid.php

2. Using the clues that are available, construct a 3x3 Polybius Square.

"We started with zero and ended up with nine. After throwing out six..."

Using the numbers 0 through 9 (but skipping 6), fill in the square, starting at the
upper left and moving across and then down. Label the rows and columns
as 1, 2 and 3.

3.  To begin the decryption, locate the "Key Word".

"...we came up with 35 45.588 044 80.490..."

The Key Word is: 35 45.588 044 80.490




4.  Decrypt the Key Word as follows:

Take the first number (3), and locate it in your polybius square. The '3' is in row 2, column 1. Write down the row number with the column number directly below it. Locate the next encrypted number (5) in the polybius square. It's in row 2, column 3. Write the row number next to the previous row number and the column number below it, next to the previous column number. Now you'll have the start of 2 lines of numbers.  The upper line starting with 22 and the lower line starting with 13. Continue decrypting the numbers in the same manner, writing the row numbers on the upper line and the column numbers on the lower line. When you're done, you should have two rows of 15 numbers.

5.  Place the decrypted numbers in pairs, as follows:

Pair up the numbers in the top row (the first pair will be 22).  At the end of the top row there will be a single number (1).  Pair up the last number in the top row with the first number in the bottom row, then continue pairing the numbers along the bottom row. You
should now have 15 pairs of numbers.

6.  Use the paired numbers and Polybius Square to decrypt the solution as follows:

The first pair is 22, so go to row 2, column 2 on the Polybius Square to find the decrypted coordinate number, which should be 4. The second pair is also 22, so the decrypted number should again be 4. The third pair is 23, so the decrypted number, in row 2 column 3, should be 5. Continue on, and the string of decrypted numbers should begin to make sense.

7.  The decrypted number is your solution.

Solved Coordinates:

     N 44 57.475, W 089 41.417     

8.  Use GeoChecker to verify the accuracy of your solved coordinates.

GeoChecker - HBD Puzzle