Posted on 14 May 2015

## Puzzle

*Today's Challenge with test your skills of cryptography, visual research and sequential thinking.*

Semiotics...

## Hint 1 |
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The top part contains the instructions for decoding the message at the bottom. (It works better if you assume that the first circle in the second line is red rather than brown; otherwise it appears that one step is a no-op.)

## Hint 2 |
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There are three steps - the same steps that you would use to convert Mw== to 3, 2 to 1, and 32 to 2 (in that order).

## Solution |
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- "1" - alter it by 1 (it works better if you assume that the first circle in the second line is red rather than brown, since that translates to "2" to indicate that you need to subtract 1 to get
*to*1 -- ASCII 0x32 minus 1 = ASCII 0x31 = "1") - "32" - convert ASCII hexadecimal codes - ASCII 0x32 = "2"
- "Mw==" - convert using Base64 encoding - Base64 "MW==" = "3"

The order of these steps used for decoding are #3 first, then #1 and #2.

So we start with the text at the bottom of the card in the image:

NGUgNGEgNGUgNDYgNTAgNDggNTMgNDIgNTEgNDkg

We decode it using Base64 encoding to get:

4e 4a 4e 46 50 48 53 42 51 49

Subtract 1:

4d 49 4d 45 4f 47 52 41 50 48

And finally convert the ASCII hexadecimal codes to letters:

MIMEOGRAPH

The solution is stl.la/mimeograph