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PURPLEDUEL

Encodings & secrets path

6 labs · Base64, hex, ciphers

Encodings & secrets teaches a distinction that saves a lot of data: encoding is not encrypting. Base64, hexadecimal, ROT13 and mirrored text change how information looks but do not protect it, because anyone can turn it back into plain text without a key. In the labs you recognise these formats by their look, peel them off one layer at a time even when they are stacked, extract readable text from a compiled program and understand why real protection needs real encryption, salted hashes and a secrets manager.

The labs, in order

  1. Base64 is not a secret

    easy · 300 XP

    There is a message in the folder that looks like gibberish: letters, digits and an '=' at the end. A careless technician "protected" it this way. Find out what it hides and recover the flag.

    Requires: Reading in pieces.

  2. Hexadecimal

    easy · 350 XP

    A traffic recorder captured a message and saved it as a long string of digits and letters from a to f. Learn to read hexadecimal, turn the capture back into text and recover the flag.

    Requires: Base64 is not a secret.

  3. Caesar's cipher

    medium · 600 XP

    At the old market notice board the Crow leaves his messages: one is written with a cipher that shifts the letters, another one "in a mirror". Decipher both and find the vault code.

    Requires: Hexadecimal.

  4. Secrets inside an executable

    medium · 600 XP

    A company handed you a compiled program, the vault, and swears nobody can read its secrets. Prove it wrong: extract the service code left inside the file.

    Requires: Hexadecimal and Searching text.

  5. Layer upon layer

    medium · 600 XP

    The Crow sealed his message like an onion: several encodings, one on top of the other. One command is not enough: chain several with the pipe and peel off the layers in the right order.

    Requires: Caesar's cipher and Pipes and filters.

  6. The final riddle

    hard · 1000 XP

    The Crow has vanished, leaving a locked chest and a few clues scattered across several files: a legend, an order, a program. Rebuild the riddle, reopen the chest and find out why encoding is not encrypting.

    Requires: Secrets inside an executable and Layer upon layer.

Commands in this path

Along this path the simulated terminal has you use these commands: cat, base64, xxd, tr, rev, file, strings and grep. Each lab page explains what they are for.

Learn more with the guides

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The other paths

The PurpleDuel labs