Codes and Ciphers.
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Mono-alphabetic cipher notes.Caesar shift, keyword, random substitution, affine shift etc. Grid ciphers. (Playfair etc.)Playfair and double playfair. Transposition ciphers. (Railfence etc.)Railfence, shuffle etc. |
Poly-alphabetic ciphers ciphers. (Viginere etc.)Viginere, Beaufort, autokey, onetime pad, digraph etc. Frequency Analysis. Notes Tables and standard results etc. JavaScript monoalphabetic ciphers frequency analysis. Use associative array sorting to make a bargraph of ciphertext letter frequencies and then compare the result with standard English letter counts. JavaScript polyalphabetic ciphers frequency analysis. Use associative array sorting to make a table of ciphertext letter frequencies and then compare the result with standard English letter counts. Excel Code Tools. How to make tools to use in codebreaking with EXCEL and VBA |
Bare Bones JavaScript Tools.These tools do one job each and in the simplest way I can think of doing it. They have very little else on the web page so that they don't look good but they di mean that you can get at the JavaScript code very easily. Simple shift cipher version 0. This moves the alphabet backwards and forwards and decodes each time it moves. Probably the simplest JavaScript decoder. Simple shift cipher version 1. This moves the alphabet backwards and forwards to produce cipher alphabets. It will encipher and decipher using a slightly more complex method than the previous sheet. JavaScript frequency analysis. Use associative array sorting to make a bargraph of ciphertext letter frequencies and then compare the result with standard English letter counts. | |
National Cipher ChallengeThis is a National code breaking competition running from September to December. It is organised by Bletchley Park, Cambridge University and GCHQ. Previous challenges 2002-2012 mostly complete. My archive - see below for better. GitHub National Cipher Challenge Archive. (Unofficial but very good!) | |
Useful LinksCipher Challenge. The national cipher cracking competition homepage. Bletchley Park resources page. Bletchley Park was Britains code breaking HQ during WWII. This page contains lesson plans and downloadable goodies. Simon Singh's Homepage. Simon Singh is the author of "The Codebook". His website provides an excellent introduction to the whole are a of codes, ciphers and code breaking. Cryptology Links Page This page has a huge number of code cracking resources. We can't vouch for what they might do to your computer though! Wikipedia Wikipedia has lots of very useful pages on all the ciphers that you are likely to encounter in the Cipher Challenge competition. Nova TV Nazi Secrets page. This has a few pages on real cipher systems and three very, very hard decryption problems. |
last updated 21st September 2014