Cicada 303. — GCBQ2Z0 Walkthrough

This walkthrough follows the puzzle trail for the second Cicada 303 cache, GCBQ2Z0.

1. Start with the page cipher

The cache page contains a block of symbol text:

;‡ -‡*16(9 :‡?( .(‡3(8)) :‡? ]600 *88† ;‡ ?)8 ;48 78: 5356* ;48 78: 45) *‡; -45*38† ;48 78: 6) 95†8 ]6;4‡?; ;48 *?928() 2?; ]48(8 6) ;48 78: ;48 78: ]600 ;578 :‡? ;‡ ]48(8 6; 6) *88†8†

The symbols resemble the cipher from Edgar Allan Poe’s The Gold-Bug.

2. Confirm the cipher from the Additional Hints

The Additional Hints area contains a ROT13-encoded URL:

uggcf://bhg14aq3e.pbz/jc-pbagrag/hcybnqf/2026/05/uvagTPOD2M0.jni

Decode it with ROT13:

https://out14nd3r.com/wp-content/uploads/2026/05/hintGCBQ2Z0.wav

Open the WAV file in a spectrogram analyzer. The hidden spectrogram message reads:

GOLDEN BUG

This confirms that the symbol text should be solved as a Gold-Bug cipher.

3. Decode the Gold-Bug text

Using the Gold-Bug substitution, the symbol message decodes to:

TO CONFIRM YOUR PROGRESS YOU WILL NEED TO USE THE KEY AGAIN THE KEY HAS NOT CHANGED THE KEY IS MADE WITHOUT THE NUMBERS BUT WHERE IS THE KEY THE KEY WILL TAKE YOU TO WHERE IT IS NEEDED

The important instruction is that the key has not changed.

4. Reuse the key from the first Cicada 303 puzzle

The first Cicada 303 puzzle gave the spectrogram message:

AFFE3F0AD3BFCF

The instruction says the key is made without the numbers. Remove the digits:

AFFEFADBFCF

5. Click the Cicada image

The top Cicada image links to a special Certitude checker, not the normal final checker:

https://www.certitudes.org/certitude?wp=W1BQ2Z0

Enter the key:

AFFEFADBFCF

Certitude confirms the answer and gives bonus info:

You have proven yourself worthy. For final follow this link. 7hi39tv4/dge.skxnfoz

6. Decode the bonus link

The bonus link is a keyboard cipher and is also reversed.

Start with:

7hi39tv4/dge.skxnfoz

Apply the keyboard cipher:

7ph39ew4/moc.lruynit

Now reverse it:

tinyurl.com/4we93hp7

7. Analyze the final WAV

The TinyURL leads to another WAV file.

Open that WAV file in a spectrogram analyzer, just like the earlier audio clues.

The spectrogram shows the final coordinates.

8. Check the final location

Use the normal GCBQ2Z0 Certitude checker to confirm the final coordinates:

https://www.certitudes.org/certitude?wp=GCBQ2Z0
Summary path: Additional Hint ROT13 → WAV spectrogram says GOLDEN BUG → Gold-Bug cipher says the key has not changed → use AFFEFADBFCF in special Certitude → keyboard/reverse the bonus link → final WAV spectrogram → normal Certitude coordinate check.
PDF file of Walk Trough