---
# System prepended metadata

title: DeconstruCT.F 2021 | CRYPTO | The Conspiracy
tags: [writeup, ctf]

---

---
layout: post
title:  "DeconstruCT.F 2021 | CRYPTO | The Conspiracy"
date:   2021-10-03 13:37:00 +0700
tags: [ctf, writeup]
---

<figure>
    <img src="https://cdn.discordapp.com/attachments/874145963407720513/894206917239513118/Group.png">
</figure>

#### CRYPTO | The Conspiracy (150 points | 132 solves)

Challenge Description:
```
There was once a sailor who travelled to many countries. He was a quirky old man. He said many many things, and most of what he said never made sense to anyone. He considered himself ahead of his time, and said that the people of his time were unworthy of his wisdom. Soon he was lost to the ages, but his diary wasn't. Are you worthy of decoding his wisdom?
```

We're given the following file (`diary.txt`):
```python
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
```

Solution:<br>
It is base64 encoded message, so I decode it and it gives the following result:
```
dsc{(-18.05572729282756, 178.45700143131674),(19.028282857505392, 103.14426071207107),(42.536705991266146, 1.4930344612276933),(38.5893697217354, 68.81632523058967),_,(50.851518948206795, 4.360180853581986),(7.671863538453386, 36.83726095698952),_,(38.619506740587035, 34.85512642711004),(47.42806157123545, 18.998421101903602),(30.19387158353921, 31.12496611612573),_,(-0.23177559426111558, -78.5033963083949),(-12.85446936733455, 132.79262433883298),(44.424231252577435, 24.350241166279226),(24.8195647413923, 120.97236754005058),(18.584456974403487, -72.31812189614772)}
```
We can see a lot of coordinate, therefore I put it in [Google Maps](http://maps.google.com) and take the first letter of the each country and get the flag.

FLAG : **dsc{FLAT_BE_THE_EARTH}**