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Course content was made from ScioVirtual Codebusters lead faculty, including:
William Lee, captain of Mason High School’s National Tournament-winning Science Olympiad team and rising freshman at UC Berkeley. William is a six-time Science Olympiad national medalist, including two medals in Codebusters. William has taught Advanced Chemistry and Codebusters at ScioVirtual and directed Mason’s ScioVirtual chapter.
Estelle Apewokin is a junior on the Science Olympiad Team at Mason High School. Estelle competed in a few different events, but her favorite is Codebusters by far! She loves to dance, read, listen to music, and play puzzle games like Sudoku, Wordscapes, or Candy Crush :)
Pragnya Ramkumar is a freshman attending Troy High School and a captain of Sierra Vista MS Science Olympiad, medalling in Codebusters at Nationals. In her free time, I love to dance, write, and annoy my friends with quirky holidays for each day of the year!
William teaching patristocrats in ScioVirtual’s live Codebusters course.
William teaching patristocrats in ScioVirtual’s live Codebusters course.


Codebusters is an event all about solving ciphers, or writing that has been encoded. There are generally three types of ciphers — ciphers where one letter is substituted for another (mainly Aristocrats and Patristocrats, and Xenocrypt, which is the same thing but in Spanish), math ciphers where numbers are used to represent numbers, and other ciphers (Pollux, Morbit, and Baconian) which use either As and Bs or Morse Code.

Codebusters is also a unique event in terms of its structure. 1) It is an event in which you compete in teams of three. 2) You cannot use a cheatsheet or binder, only the reference materials provided to you as part of the test. 3) There is a timed question. The timed question is always an aristocrat, and points are awarded based on how early you finish up to ten minutes.

The best thing about Codebusters is that it’s very formulaic. You know exactly the types of ciphers that will show up on the test, so as long as you practice those well, you should be prepared for success. The #1 site used by Codebusters for practicing aristocrats is cryptograms.org. You can play for speed and compete with other players. Other good links for practice can be found on the document on the right.

Below are some other good resources from ScioVirtual classes that teaches each cipher.

1️⃣ Single-Substitution Ciphers

Practice Sites:
  • Puzzle Baron Cryptograms - timed aristocrats; can get hints, make an account (with your parents’ permission), and see how fast other people solve each aristocrat
  • Cryptogram.org - can paste ciphers into this to solve them; or the site can generate a cipher for you to solve, give hints, and show you the solution
  • Toebes - can make or take Codebusters practice tests

⬆️ Aristocrats, Patristocrats, and Xenocrypt

⬆️ Caesar and Atbash

2️⃣ Math Ciphers

Letters to Numbers Quizlet

Letters to Numbers Kahoot

⬆️ Affine, Vigenere, and Hill overview

⬆️ In-depth Vigenere with practice problems

3️⃣ Other Ciphers

⬆️ Pollux and Morbit, which use Morse Code

⬆️ Baconian, which uses binary or As and Bs

Practice test

There you have it! Every single type of cipher used in Division B competition is covered in at least one of these presentations. And actually, for Division B, you don’t even have to learn the Hill math cipher (this is Division C only), so that’s even less that you need to cover. The bulk of this event remains consistent practice, so make sure to use the links in the Event Resource Sheet to do so.