Arnold Chopper? | CyberStart Completion

Arnold Chopper?


A few days ago one of our field agents, who is now working undercover for The Choppers, found two pages of a book ripped out and left on a table.

We weren’t sure if it meant anything, but then today we intercepted an email containing some cryptic code. It looks like the gang is getting smarter with its encrypted messages and is now using Arnold Ciphers.

See if you can use the intercepted code and the two pages of the book to discover what it means.

Tip: We believe the message contains a code, that’s the flag.


An Arnold or book cipher is one where the numbers refer to the position of words in the text. In this case, it looks like each set of three numbers refers to the page, line and word. So 02.04.03 would mean the second page, fourth line down, third word along. Once you understand that, decrypting the message should be easy, and the flag is hidden within.

How to Solve:

  1. Since the message was decrypted using an Arnold Cipher, we need to go to each page X, count line Y on the page, and note the word number Z on the line. (Page X, Line Y, Word Z)
    1. 07.10.08 07.17.01 08.22.08 08.15.01 08.06.08 07.17.01 08.17.02 08.01.04 08.10.11 07.12.06 08.09.09 08.18.04 07.17.01 07.01.03 07.35.05 08.01.04 07.24.10 07.33.11 07.29.02
    2. Kinsmen, the commands. Go tonight, the moment is now. Lower opportunity in the morning. Code is puppet. Good fortune.


  • Puppet