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NC Science Olympiad

Codebusters

Division: A- Elementary School

NC Essential Standards Alignment: Computer Science, 68-NI-04; 68-DA-01

SEP Practices: SEP 5

Event Rules and Score Sheets: See 2025 Division A Rules Manual

Description:

Teams will cryptanalyze (decode) encrypted messages using cryptanalysis techniques and show skill with ciphers by decrypting a message.

 Event Leaders will provide scratch paper and a resource sheet for each team. The resource sheet will include English letter frequencies, Atbash, DancingMen, and Vigenère tables but will NOT provide the PigPen, TapCode, or Knight’s Templar Cipher tables

Materials:

Teams must bring a writing utensil. No other resources are allowed.

Scoring:

High score wins.

Common Mistakes:

  • Students do not have to work through each cipher together – divide and conquer the test!  You are allowed to take it apart.

FAQs

Will the students be given the Caesar offset number or will they have to figure it out?

– If we give the Caesar offset, it will be worth less than if we don’t, but they might see it both ways!

What is the best way to study for this test?

  • Make test in the Codebusters tool – this is how all the tests will be made this year, so students should get used to the format.  They can make ciphers for each other too – you can’t break it, let them take a sentence and change the cipher type to see how it changes what will print on the page!

Event Resources:

Codebusters Test Tools
The State event supervisor for Codebusters has set up a twitter handle to send out tips and tricks.  @NCSO_cb
 
 
Previous tests can be found at http://toebes.com/Ciphers/index.html
Cryptoclub
CIA – break the code
Cryptograms.org
Test Builder Demo
Hill Cipher
Affine Cipher
   Encode/Decode Tool:   http://www.dcode.fr/affine-cipher
 
Vigenere Cipher