## Thursday 2 April 2015

### What’s the password?!

It can be tricky thinking of engaging ways to help explain some topics on the new computing curriculum. One idea is to find a 'real life' problem and reflect it in that; so when it came to designing a task for the topic of ‘using logic reasoning to explain algorithms’, I was debating what would be best to use.

It was during this ‘thinking period’ that I tried to enter my kitchen at home, to be met with "what's the password?" My seven year old daughter does this quite often: she loves the idea of passwords. Soon after, I was allowed in when I guessed one of the usuals (the word 'purple') and I thought of the idea for our new task.

With so many login details that we as adults even struggle to remember, creating strong yet memorable passwords is important for us as well. Bob and his family were created - a family of four who struggle to remember passwords, so Bob, the father, creates an easy-to-use algorithm for his family which they can all use, yet it produces different passwords depending on what's in each 'variable'.

It’s a ‘current’ topic and a problem of many, but also a simple and effective way of explaining how an algorithm works. It also made for a mystery which adds to the digital literacy section of the curriculum – keeping personal information private!

I personally use an algorithm for creating passwords, and it's worked great for me so far, so what's good for me is good for Bob! The main thing is it creates a memorable and strong password for any website based on a combination of input variables and some rules. These are simple inputs such as their names, a secret number and a website name. It will help with explaining a number of concepts in one go.

 One of the slips
By introducing all this through a story about a person coming up with a way to help his wife and kids generate and remember passwords, it is possible to include all these ideas into a nice story thread that will not intimidate KS2 students. This can also be used to explain how the same algorithm generates different outputs based on different initialization values and input variables. It can also challenge students to come up with their own password generation algorithms.

Students need to understand that algorithms are not limited to computer programs and this task provides a good example of one that they can use any time – such as to stop unauthorized people going into kitchens.

You can find out more about this mystery by clicking here. To try it (£1.49), search 'Digital Mysteries Algorithm' on the App Store or click here. To download a trial of the Windows PC/laptop software click here.