This square of coloured squares is a representation of the hash generated by a hash function using the text typed in the box.

A hash function takes some stuff, in this case the text in the box, and mixes it up to produce a fixed string, in this case a 256-character string of the digits from 0 to 3.

You can see these numbers above in the "fourhash" box above. These numbers are then mapped to four colors to produce the coloured square!

So if you are still reading and still wondering why anyone would do this and waste your time, there are a few reasons:

• it's beautiful!
• it's (probably) unique!
• it demonstrates several neat properties of hash functions

Those properties are:

• a small change in the text produces a large change in the output of the hash function!
• the exact same text produces the exact same hash output
• the odds of two strings of text producing the same hash might be very small, like one out of the number of grains of sand on all the beaches small!
• and if I give you the hash and the function that made it, it's impossible(ish) for you to figure out what the original text is!

Pretty cool, huh?!

So, if you have further questions, you'd probably make a pretty good cryptographer. Hash functions are important for keeping communications secure, but, they have a beauty and elegance, I think. It's fun to look for patterns in what looks random, but isn't (or is it?) I like to type letters and watch the colours change.

Originally I made this with a beefy common hash function SHA-1, but that seemed like overkill and I wanted to make my own hash function so this uses RFNG-2, or "Robbie's Fragile Number Garden, version 2". If you read the code, you can get an idea how it works. It is fragile, so don't use it to verify encrypted messages to grandma. I'm working on writing up the algorithm it uses, and it's way better than RFNG-1!