Girls Go CyberStart is a fun series of cyber challenges where a curious mind and a willingness to try are your best tools. You don’t need any cybersecurity background to succeed! But if you like to warm up your cyber muscles before a race, these Practice Puzzles will give you a look at the types of challenges in GGCS along with tips and tricks to solving them. You could be solving challenges like these soon! Find out more and sign up to get competition updates here.
Puzzle #1: a simple cryptography puzzle type often seen in cyber competitions. Hint on a good tool to use: Rumkin
Ltetwl, tg tgvbxgm knexk & labym vbiaxkl — tee gtfxw Vtxltk!
Solution — The first step to solving a cryptography puzzle is to determine what type of cipher was used. A “cipher” is an algorithm or a set of specific steps used to turn plain text into scrambled data so that it looks like babble to anyone except those who know the trick to decoding it.
Did they use Substitution where every letter in the alphabet is replaced with another letter, character or symbol? Examples of Substitution ciphers are Rot13, Pigpen or Morse Code. Or maybe they used Transposition where the way the letters are arranged is the cipher? Examples are Columnar or RailFence. What? You’ve never heard of these? That’s where the hint comes in. Rumkin.com is one of many good online resources to discover types of ciphers and it comes with tools to help solve cipher puzzles.
Puzzle #1 used a Shift cipher, a substitution type cipher which takes the alphabet and shifts it a certain number of places. In this case we shifted left 19 places so that we get the substitution key seen below. Plaintext A becomes ciphertext T, plaintext B becomes ciphertext U, etc.
So now we can decode this! We can do it by hand OR we can go to Rumkin.com to use the Caesarian Shift tool. The answer is:
Resources: For more practice with substitution ciphers, try the NSA Crypto Challenge of the Week. Have a favorite crypto decoding website like Rumkin.com ? Share it with us in the comments!