Cryptography and number theory
Secret messages reveal why patterns matter.
This prototype introduces classical cryptography through Caesar and Vigenere ciphers, then uses frequency analysis to ask how a weak cipher can be attacked.
The aim is not modern security. It is mathematical curiosity: keys, shifts, structure, evidence and the joy of trying to break a pattern.
Cryptography lab
Hide a message, then look for the pattern that gives it away.
Classical ciphers are not secure today, but they are a brilliant way to see the mathematics of keys, frequency and structure.
Letters used
48
Cipher
Caesar
Key
7
Encrypted message
Thaolthapjz pz mbss vm whaalyuz dhpapun av il kpzjvclylk.
Grouped version
THAOL THAPJ ZPZMB SSVMW HAALY UZDHP APUNA VILKP ZJVCL YLK
Decrypting with the chosen key gives:
Mathematics is full of patterns waiting to be discovered.
Break the cipher
Frequency analysis looks for statistical fingerprints.
The green bars show the encrypted message. The grey bars show rough average frequencies in English. Short messages can be noisy, but longer messages often reveal useful clues.
Caesar attack
Try every shift.
A Caesar cipher only has 26 possible shifts, so it can be broken by brute force. The table ranks shifts by how English-like the result appears.
Guided tasks
Joy in the process
The point is not just to finish. It is to notice, test and return.
These tools are invitations to explore. A good mistake, a surprising pattern or a question you cannot yet answer is part of the work, not a failure of it.
The challenge is deliberate: the site should support thinking, not remove the need for it.
Future extensions