Posted on 5 June 2015

## Puzzle[]

*Today's Student-submitted Challenge will test your skills of cryptoanalysis, languages, visual manipulation and calculation.*

This French isn't bad language, but you must zoom and paint to see. Then Pie is good dessert to step away, from home to end, count only where our are, the others taste awful.

## Hint 1 |
---|

For the "you must zoom and paint to see" part of the clue, zoom in to the pixel level and use a graphics editor to erase the main colors of the numbers.

## Hint 2 |
---|

For the "Pie" and "from home to end, count only where [they] are" part of the clue, start with the first two digits of a well-known constant. If you count off the number of positions corresponding to the first digit of that constant, and then the number of positions corresponding to the second digit from there, where do you land?

## Solution |
---|

There are a number of steps involved in decoding this message:

- Convert the hexadecimal numbers to ASCII text. This results in: pour trouver la reponse il faut chercher le cercle dans la profondeur de ces lettres. It translates to: to find the answer must be sought the circle in the depth of these letters.
- There are variations in the colors of the hexidecimal numbers. There are three groups of 23 with the same color. The color of the first group is (4a,4f,49), the second group is (4e,54,48) and the third group is (45,4d,55). Converting those hex color codes to ASCII text reveals the message "JOIN THE MU". That message does not appear to have anything to do with the puzzle other than a reference to the line of the puzzle's author.
- For the "you must zoom" part of the clue, use a graphics editor to zoom in to view individual pixels in the numbers.
- For the "paint to see" part of the clue, erase the main color in each group of 23 hexadecimal numbers. This allows you to see some dots that are slightly different colors in each of the hexadecimal digits.
- The clue mentions "pie" and the converted text talks about "the circle in the depth of these letters". These suggest using the value of Pi, which is a constant related to measurements of a circle, in some way.
- For the "to step away, from home to end" part of the clue, start at the beginning (home) and count off the number of positions for the first digit of Pi (3). That points to the group of dots inside the braces to the left of the decimal point. Starting there and counting off the number of positions for the next digit of Pi (1) points to the group of dots inside the braces to the right of the decimal point.
- Since that gives us a good reason for having the braces and decimal point in those specific positions, continue counting off positions based on the following digits of the value of Pi, which are {3}.{1}415926535897 (the red numbers in the image to the right). Thus, counting 4 more positions points to the group of dots where the "75" at the beginning of the second row had been, counting 1 more position points to the following group of dots where the "76" next to it had been and counting 5 more positions points to the group of dots where the 72 at the end of that row had been. You might imagine braces around each of those selected positions, indicating that something needs done with the dots in those positions.
- Now count the dots in each of the selected positions. In order to get two-digit numbers, count the dots on the left and right of each position separately. And to get hexadecimal digits, 14 dots = the hex digit "e" and 15 dots = the hex digit "f". This results in: 6f 63 65 61 6e 70 61 63 69 66 69 71 75 65 (the black numbers in the image to the above right).
- Converting that to ASCII results in oceanpacifique (French for "Pacific Ocean"). The answer is stl.la/oceanpacifique .

## Reward |
---|