Substitution Cipher Decoding Utility

Substitution Cipher Decoding Utility

Somewhere along the way in delving in to cyber security, I’ve also gained an interest in encryption. While this might seem obvious, I’m more interested in the classical cryptography such as substitution ciphers, transposition ciphers and the Vigenère Cipher.

For anyone with an interest in cryptopgraphy, I highly recommend [easyazon_link keywords=”The Code Book by Simon Singh” locale=”US” tag=”bobmckay-20″]The Code Book by Simon Singh[/easyazon_link].

Just the facts, take me to the tool >

My Caesar Cipher Wheel (see below)

I decided to have a go at cryptanalysis of substitution ciphers to see how hard they would be to decode.

There a quite a few tools out there but none of them quite did what I wanted to I decided to dust-off my coding hat and create a tool that does the frequency analisys (the heavy lifting) for me, as well as providing some suggestions of matches.

The decoding utility uses a mixture of PHP for the initial frequency analysis combined with JavaScript for manipulating the cipher and plaintext content.

There’s definitely room for improvement but at the moment I’m focusing on creating a tool to solve the more complicated Vigenère Cipher so I’ll have to come back to this!

Go to the Substitution Cipher Decryption Tool >

Caesar Cipher Wheel

As a related project, I also wanted to do some simply secret code writing with my kids so I made a Caesar Cipher Wheel and have published the printable design here:

Bob McKay

About Bob McKay

Bob is a Founder of Seguro Ltd, a full time father and husband, part-time tinkerer-with-wires, coder, Muay Thai practitioner, builder and cook. Big fan of equality, tolerance and co-existence.

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