## Hackthebox challenge writeup - Templed Tweet

## Introduction

This is my first crypto challenge. I have no idea what I am up for.

The challenge start with the download of a .zip file, and inside that you find a file *Scroll.png*

My first thought is that this is some kind of substitution cipher, meaning that each of the signs in the text represents a letter.

So I counted up how often each sign is represented in the text, so that I can compare that to a frequencytable I found on Wikipedia https://en.wikipedia.org/wiki/Frequency_analysis:

What can we assume?

- 16 characters.
- 14 unique characters.
- It can be one or multiple words.
- The word(s) might be separated, or not.

Let's line up what we know:

```
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
x x x x x x x x x x x x x x x x
_ _ _ _ _ _ y z _ _ z y _ _ _ _
# If we trust the frequency analysis we can try substitute our multiple occurences according the chart
_ _ _ _ _ _ e t _ _ e t _ _ _ _
_ _ _ _ _ _ t e _ _ t e _ _ _ _
```

This look very crossword-like to me, so lets try a tool designed for solving crosswords: https://crossword-dictionary.com/

We do have some hits with the *te* patterns in it. But if we examine the results, none of them can be correct given that
we know:

- That
*te*/*et*is the only pattern we have. - That
*t*and*e*is the only letters occuring more than once.

This approach did not work out, so the thoughtprocess is kickstarted.

## Looking for visual clues

The challenge is called *templed* and the image is named *scroll*. The text that comes with the challenge hinting about
a *temple*, so let transform the image to see if we can learn more about it.

- Original
- Flip Horizontal
- Flip Vertical
- Rotate 180
- Rotate 90 clockwise
- Rotate 90 counterclockwise

## Looking for different symbolciphers on the Internet

So far we have avoided searching the obvious keywords on your favorite searchengine. But I suspect this challenge to be really easy to solve if we just find the correct source of information.

I start at my favorite cryptosite: https://www.dcode.fr/en and search for symbols.

After some more searching we find this nugget: http://www.davidaking.org/Ciphers.htm:

## Counting the oldschool way

As we can se from the chart, every number consist of a stem '|' which is varied by attaching various additions. I.e every sign in our secret message which contain the shape 'L' is a "1xy".

If we apply our new knowledge to our solution we will end up with this translation:

Which in a more copy-paste friendly way is:

```
72 84 66 123 77 48 78 107 115 95 107 78 51 119 33 125
```

I have a feeling that we are not quite done yet. These numbers might translate into letters somehow, so let find a number-to-letter translator: https://www.boxentriq.com/code-breaking/numbers-to-letters

```
HTB{M0Nks_kN3w!}
```

Congratulations, you have solved the crypto challenge.

## Comments