Hidden Location
🔍 Details
| Attribute | Details |
|---|---|
| Challenge Name | Hidden Location |
| Category | OSINT |
| Difficulty | 🟠 Medium |
| Flag | F4H{8uQIpHKqpJ**********} |
📝 Description
You’ve uncovered an encrypted flag — but unlocking it requires two things: the correct key and the name of the cipher used to encrypt it.
The key is the last name of a renowned cryptographer, hidden in a specific place. Interestingly, the cipher shares a name with this cryptographer — find one, and you find both.
A set of coordinates may point you in the right direction: reactors.beekeeper.unfrozen
📥 Download encrypted_flag.txt
🧩 Hints
- Three Words, One Location
💡 Solution
- Interpret the Coordinates
The provided three-word address on what3words.com (opens in a new tab):
reactors.beekeeper.unfrozen
Leads to:
15-9 Rue Blaise de Vigenère, 03500 Saint-Pourçain-sur-Sioule, France
This street is named after the famous French cryptographer Blaise de Vigenère, the inventor of the Vigenère cipher.
Thus, the challenge gives us:
- Cipher:
Vigenère - Key:
Vigenere
-
Decrypt the Flag
Use any Vigenère cipher tool to decrypt the flag.
📚 Insights
- what3words is a geolocation system that assigns each 3m x 3m square a unique three-word address.
- It's often used in OSINT and CTF challenges to hide precise coordinates in a human-readable format.
- In this challenge, the location pointed to a street named after Blaise de Vigenère, revealing both the cipher and the key.
- The Vigenère cipher is a polyalphabetic substitution cipher that encrypts text using a repeating keyword.