A message in two layers | Hunt the Flag

Labs need a computer

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Files

crypto-layers.zip
Size: 526 B
SHA-256
da5826534eab108c443257a449cd24935de22a14b040411fba43bc1ab91d7537
Download

After downloading, compare the file SHA-256 with the value shown here to make sure it arrived intact.

Tools you may need

CyberChef
A browser tool for trying decodings one after another.

Scenario

In an old settings file you find a strange line left by a developer, with a note saying it is "encrypted twice for safety". There is no key anywhere.

What you are looking at

You download crypto-layers.zip containing a README and message.txt with a line encoded twice. There is no key anywhere, which is itself the clue that this is encoding, not encryption.

Goal

Turn the message back into its original text and extract the flag.

What counts as solved

You enter the correct flag in the box.

Method checklist

Tick each step as you work through it. The steps are the method, not the answer.

Unzip the file and read the README and message.txt.
Note the characters used: letters and digits, perhaps an = at the end.
Try Base64 directly; if it fails, the letters were shifted first.
Undo ROT13 then Base64 and extract the flag.

Hints

You have not revealed a hint yet. Ask the falcon when you need one.